What is involved in Changing Tranny/Engine Mounts? How difficult is the process?

Not too difficult, on 94-96, you need to raise the car enough so you can work under the car safely, use jack stands.

Loosen the front engine mount, trans mount, the top dog bone mount, and the side trans mounts. Once loosen, you need to raise the engine and trans so you can remove the side trans mount, it has a very long bolt that requires it to be raised off to remove. You will also need to disconnect the axles, sway bar for this as well so you can manuveur the engine/trans.

While you are in there do an oil change, you will notice when you remove the front engine mount, bunch of oil oil trapped behind the mount will spill out 1/8 of a quart, I know I was surprised, it also makes it easier to toque the new oil filter.

well, there's 5 in total. depends which one you want to change.

all the mounts except the rear engine mount is easily done with the car on jackstands.

rear engine mount.....i'd suggest just let a mechanic work on it, not worth the effort because it involves a mount housing that has a driveshaft going through it with a carrier bearing that always seize into the housing. needs to be pressed out by a hydraulic press and replaced everytime the mount gets changed.

+1 leave the rear one alone, just consider the 2 front, driver side trans and upper dog bone.

How much on average would a mechanic charge to change the engine mounts, nd the transmission mounts. Is there a noticable difference after changing them? I have a slight vibration at idle and have 170k miles and wondering if its worth changing

Check out your dog bone, I bet it is ripped. the difference is noticable, don't go cheap aftermarket, I placed an aftermarket one and it only last a year. If your idle is off it will not help.

Sorry do not know how much a wrench would charge.