There's only 1 company that specializes in that, and unless you are in FL and willing to pay half to 2/3 the cost of replacing your counters to make that happen, you are out of luck with almost anyone willing to take the risk. Because it IS risky.

Looking at the granite on the underside, are you sure you don't want to replace it too? And have you found a replacement sink with the exact cutout as your old sink?

The counters are soapstone and I do not wand to replace them. I have found a sink that will fit, the current cutout is typical dimensions.

I am hoping that Joseph Corlett will give me his advice, maybe should have just messaged him directly. The sink is silgranite so maybe it could be sawed apart.

I once asked @Joseph Corlett, LLC how you replace an undermount sink without replacing the countertop. I wish I had bookmarked it at the time, but he made it sound very straightforward. I did search for his reply for you, but he has kindly replied to so many of my questions over the years I couldn’t find the thread. I hope he stops by for you.

"Because it IS risky."

There is very little risk in replacing an undermount sink.

Middle of the night idea I had was to use a hole saw to drill though the sink in the area where the screws are to access them but they are pretty close to the counter top edge so not sure that would be a great plan. IDK, I detest the current sink but am not sure I can find someone I trust to take apart the cabinet and get it back together.

" There is very little risk in replacing an undermount sink. "

For some, maybe. Most of the helpers in stone shops out there aren't' hired for brains, but brawn. The ones that are hired for brains stay glued to the computer programming the CNC. They don't get field experience. Replacing a sink is a good way to break the countertops with the brawny ones, and an even better way to break the cabinets with the think they are smart ones.

sm:

Verify that your composite sink has silicone, not epoxy, between the sink flange and the stone bottom by seeing if you can tap a stiff scraper between them. If it's silicone, beat the sink out with a hammer, clean the stone bottom, dunk the new sink through the cutout, clamp and strap it into place.

This looks like a good job for an Oscillating Multi-Tool . Milwaukee has one. I'd cut into the center area of the plywood braces and lessen damage to the cabinet.

Thanks for the help. I have a couple of things to finish up before I can approach this but will report back on how it goes once it''s done.

"This looks like a good job for an Oscillating Multi-Tool . Milwaukee has one. I'd cut into the center area of the plywood braces and lessen damage to the cabinet."

You can't fit a Multi-Tool between the sink and cabinet side to access the blocking. That's why you tap the cabinet front off. Now you can drive a wrecking bar between the blocking and the cabinet side and/or top.

The sink looks like it is barely supported on the left side so my first approach will likely be @Joseph Corlett, LLC's idea to wedge a scraper between the sink and counter and hopefully it will just be silicon and will loosed and then I can use a mallet to knock it off that side. If it comes down to cutting then I will probably use a hole saw bit and drill through the sink at the screw locations. I tried to wedge a thin saw blade in between the wood and it would not fit but I imagine that @dan1888 is saying to just cut through the blocking and screws with a carbide tooth blade.

Yes, an oscillating tool blade mexes out at 3". Not enough to make that tool usable for this job. We find another tool to bore through the plywood. A 12" brad point drill bit could work.