Thread necromancy but this one was Duck Duck Go relevant when I searched for something similar. I just did this job. Its probably best to remove the wiring first.
My order w/o safety warnings like be safe with your jack stands:
Undo negative battery cable
Undo heat shield, it has two 8m bolts and one nut. There is one top rear that is somewhat a pain.
See if you can't remove the wiring from your bad starter carefully, my fitting broke. Long bent needle-nose for the solenoid plug and a few different shaped 13 mm wrenches / sockets for the battery cable. This requires some dexterity. The battery cable could be 2cm longer, it is too tight in my opinion but whoever owned Chrysler that day saved $.10 per vehicle. I'm angry about this, it was a waste of time not making America better.
There are three fifteen mm bolts holding on the back of your starter. loosen up the bottom one but do not remove. Remove the middle one and the ground wire which is in the way of the top bolt. Remove the top bolt.
Do what you have to do to get the starter and shim out of there w/o destroying the shim. It is not very easy to get out but it does come out w/o lifting the engine or anything. Pay attention to how the ship comes out.
Installation is almost reverse of removal. I wrestled for a few with the battery cable. The best method would probably be to guide the new starter and cable together before bolting on the starter.
Don't mess up the orientation of the shim.
As a side note, I checked the threads in my Remy replacement starter but did not drive the bolts in all the way. I had to shorten my top bolt for some reason to get it to thread the last 7.5mm or so.
Starter sounds great. I'm hunting down a new solenoid plug because mine broke and while it does function it can't be the best of connections for snow and slop.
How important is the shim?