I called Kimber and they said that I'd have to: (a) buy one attached to a new MSH, and (b) send the gun to them for installation, because it requires some "gunsmithing" to replace.

Has anyone done this before on their own?  I have punch set and Dremel, but I'm not a gunsmith either.  Thinking about the Smith and Alexander (S&A) mag well (or some other equivalent).

I'm hoping to hear that this is no big deal to do at home.  Thanks in advance.

It's no big deal to do at home.
Also the SMITH & ALEXANDER are much nicer than the Kimber ones IMHO.

I put Wilson magwells on several 1911s, and the only issue I have had is the grip panels not sitting flush on rigid panels.....this is the type that secures by way of the grip screws..... I have never had an issue, and it is not a permanent alteration to the gun.

Pachmayr grips conform nicely around the arms of the magwell, but they are soft rubber.

YMMV.

Pilk

Put a Ed Brown mag well  purchased from Midway USA  on my Kimber stainless II. Midway had the best price. It is a drop in part and are supplied on both Kimber and Springfield custom autos.

I put an S&A magwell on mine the only thing I had to do was file some metal off of the MSH where the two little legs meet the grip safety, it was causing the series II part that comes out of the frame to come up a bit to much because it was slightly depressing the grip safety. I took maybee 1/64-1/32" off of the MSH legs. No biggie at all just take your time.
As far as the Wilson magwell, I've seen a couple guys take a peice of sandpaper and use it as a shim for the grip so everything fit nice.