I would have said that I'd live with the sink awhile & see if I liked it, the material? that it's made from, etc. A lot of people here have the quartz composite sinks (like Silgranite) and really love them. But, given the contrast between dark countertops & a white sink, I understand why you want to replace it. So....

Can it be removed? No way for us to know because we don't know if the sink rim is sandwiched between granite & plywood (probably). Or if the sink rim extends out over the top of the cabinet sidewalls. Or if the sink cabinet has a face frame or center stile that would prevent getting the sink out of the cabinet even if it can be unattached from the countertop.

That said, and in next to worst case scenario, I suppose it would be possible to remove the sink in pieces and to replace it with a drop in sink. As much as I love the sledgehammer phase of renovation, I'd call a pro & inquire about more gentle methods of removal. Maybe sawn loose?

Worst case, of course, would be removing the countertop & that will most likely impact whatever backsplash you might have.

Thanks ci_lantro. I'm pretty bummed about the sink. It is an 8 yr old, at one time bright white, Corian which is now very yellowed and marred. The realtor claims the granite was original; I'm skeptical. I big white farm sink would look good, but not this...really. The sink was on my list of "cons" when we bought the house; I should have been more thorough in checking out the ease of replacing it.
We are still in our old house, so I'll have a look next time I'm at the house and see if I can tell how it was installed. There are the usual 2 doors at the front of the cabinets, but I think the divider is decorative rather than support. Also, there is a window behind the sink so it might be possible to keep the backsplash safe during removal.
I'll definitely call a pro. Should I call a plumber, granite person or a demo company? This seems like the kind of project that no one will want because of the time and hassle.

Probably the best thing to do would be to call a Corian dealer and a few plumbing shops about removing it. If you can find a plumber who can do it, will probably be cheaper considering you'll need a plumber to install the faucet & drains.

Call the oldest granite fabricator shop in your area first. Replacing an undermounted sink can be done, but it's VERY VERY tricky to replace it with anything other than a sink with the exact same profile as is already installed. I'd also take a paper template of the sink cutout and have that with you and go shopping to local plumbing supply stores and big boxes. Compare the cutout in the granite that you have with the cutout needed for the undermount sinks on their shelves. You'll probably pretty quickly see whether or not your sink is so large that replacing it won't be feasable. Even if your sink is small enough so that making a cutout for a larger sink is feasable, it's going to probably require that that section of countertop be removed and reinstalled. So, call the granite guys first, and be prepared for some sticker shock. This type of very tricky but small job won't be at the top of their favorite things to give you an estimate for, and they will require a waiver about potentially damaging the granite or sink cabinet. If you have a very common granite that doesn't have much color variation and potentially could be matched with a piece at a local yard, it'd probably be easier to do that with a new sink cutout done at that time.

If it's not doable, Corian CAN be rehabilitated to look clean and new. It'll still not match, but it makes a decent sink. I'm a big fan of stainless sinks, but I've been stuck with Corian in my 'new' house while waiting for the courage to remodel and I'm starting to like the sink. At least yours isn't pink.

Fori, LOL I am grateful it's not pink!! In my ignorance I thought my biggest problem was going to be the decision to replace with stainless steel or go for copper. SS was my final answer, but I do love the look of copper. So much for my plans ;-)
Thanks for all the advice live_wire_oak! It looks like this project is going to be dreadful. The sink is a basic 2 bowl sink and I'd like to replace it with a single bowl, ideally one with an apron. In my ignorance I thought the granite could be "adapted" in place to the new sink's "footprint."
I think the granite is a pretty common so perhaps the simple solution is to see if I can replace the section with the sink. Do people mix countertops? Wonder if I could replace the sink section with something different; just a thought. Although someone else might look at 2 different granite that same way I look at white Corian with dark granite ;-)

You might want to repost this question with something in the title about cutting installed granite or something stone-ish to get the stone people's attention. You'll need some granite removed for an apron-front sink...and the sink cabinet will need to be modified...eek.

How about filling the sink all the way up with really dark coffee overnight and call it a match? :)

You could probably do a drop-in sink easiest. Not the look you wanted, but doableest. (How many Es in 'doable-est'?)

Thanks for the advice fori. I'll post again as time gets closer and if I still have any money left ;-)

I think I'll take your advice and have the Corian fixed and adapt for awhile; perhaps a new faucet too. I guess I really had my heart set on a single bowl and we are so used to putting hot pans in the sink, which I hear is a big no-no with Corian. Is that true?

I saw some pictures in the forum of some lovely dark granite counters with white sinks. So my dislike of the white is, perhaps, not reasonable.

Doableest works for me. Thanks for the replies!

I put hot pans in and boiling water and all kinds of bad things I have since heard are no-nos. I wouldn't put something directly from the oven to sink, but I don't worry too much. (Planning to redo the kitchen has given me all kinds of liberty to test Corian out and I've been impressed. I dislike it because it looks plastic but the stuff is tough!) Apparently you're not supposed to stand in it either, but how else do you paint the pink walls over the sink?

It might clean up well enough with a bleaching. Fill it up with a strong solution overnight.