The easiest way is to hire a local landscape maintenance crew to remove it for you. Watch them to be sure all the root system is removed, particularly if you live in a warm zone.

Next easiest would be to soak the plant with Glysophate (Round Up, etc.) to kill it, then wait for the root system to die completely, and dig it up.

Finally, offer it free for the digging on Craigslist.

Hiring someone is out so it looks like we may be digging it up ourselves. I thought about chopping it low, then either trying to dig it by hand or round up it to death. Problem is I do have plants nearby I don't want any chance of being poisoned and I'd like to use the space for replanting so I've been hesitant on the round up. Do you have any idea how deep the roots might be? We just removed some stumps from three rose of sharons I chopped and round upped to death but we had access from the road so we hooked on to the stumps with my truck but this clump of grass is in the back so not so much access to it to pull it up.

I'd say your best bet is to cut it down, and then use an axe or a chainsaw to cut it out of the ground in pieces small enough to handle. I keep an old chain for my chainsaw for just this use.

You don't have to get it all in one chunk. I imagine it's got 2-3' deep major roots, and those are the only ones you need to be sure to get. Longer and deeper feeders will just die away and decompose.

I came across a suggestion of cutting it down and covering it with dark plastic to smother it out. I wonder if that would work with this plant?

I've never tried it, but if you plan to use the space for planting something else, you'll still have to dig out the crown and major rootmass.

Oh yeah right on that point because I do want to use that area

I just took a big chunk off of a friends fully mature pampas grass. It wasnt easy but, you dig a ft deep and wide trench around it with a STRONG sharp shovel. work your shovel under the roots approx. 18 inches deep and Pop it up. Then you need an axe to break up the center. Take out pieces until fully removed. Good luck

Well it's dug up and gone. Praying there will be no unsuspected blades sprouting up in the area from anything leftover.