I don't know the name of the part, so I'm calling it the front subframe. It's the part that the front lower control arms attach to. I think the steering rack is also bolted to this frame. Probably a few other items too.

Is this part removable and replaceable by just taking out bolts?

I have a 2009 xj8 with 87k miles and a salvage title. The car had an impact on the front left wheel, 30k miles ago. The guy I bought it from did a beautiful job restoring the body and it generally rides good. But that front subframe is bent where the front left lower rearward control arm attaches. This makes the front left wheel sit back about 1.5 inches in the wheel well.

I also have a 2005 xj8 with 270k miles, which is now a junk / parts car. My thinking is that if I could move the front subframe from the 2005 to the 2009, I would have a completely restored car.

 

Start by taking the old one out, see how it goes.
See just what you need to do different on the other car to improve pn your disassembly method.