Here are some additional instructions for changing the lower engine mount. Use the instructions at bay13 to start with; they are very good of course. I got stuck at a few points and this supplement might help some people who - do not have a lot of tools, have not done many repairs, etc.

You will need one of the following tools:

1) 17mm offset wrench (only recommended for installing mount and not removing it.)
2) Disk adapter to convert a 1/4” drive socket into a 3/8” drive socket. This is not the usual socket adapter that is the same size of a socket. This looks like a disc with a knob in the middle. I found this at an auto parts store, about $12 for two.
3) A non-ratcheting socket wrench with flexible head, about $10. (highly recommend)

To start, raise the car and take off the wheel. Loosen the screw that holds the material inside the wheel-well and pull back the material at the already existing crease. The night before you plan to remove the mount, spray some PB Blaster on the two 17mm bolts that go from the mount into the sub-frame. (Might as well do the 14mm bolts as well.)

Next, you will need a piece of wood. A piece that is in the same shape as the oil pan would be ideal but rather than spending an hour with a jigsaw just use some 2x material. Make the piece of wood long enough so that it just overhangs both sides (right and left) of the oil pan so that you get the benefit of lifting at the side walls of the oil pan where it is stronger. Put the wood on the jack and place the jack just behind the oil filter. Snug the wood/jack up against the bottom of the oil pan.

Remove the two 14mm bolts first, using an extension on your socket wrench. If you remove the 17mm bolts first then the engine will be wobbling around when you remove the 14mm bolts.

Next, the left 17mm bolt can be removed easiest with an intermediate size socket (I highly recommend a 6pt socket only.) The one I used was in-between the heights of a standard socket and a deep socket. (I found this at Wal-Mart one day in a bargain bin and have never seen one anywhere since.) Alternatively use a regular 17mm socket with a flexible adapter on it so you move the socket wrench around the caliper.

The right bolt is the main problem. With one of the 3 tools mentioned above you can get to this bolt, #3 is recommended because it has a very small head (compared to all of my other socket wrenches) and it has a flexible head. Using this (and a pipe extension) this bolt will easily come right off. Alternatively, you can now raise the engine using the jack and use a regular socket wrench. There have been some comments in the past about potential damage if you raise the engine too far up. You might have to raise the engine a little to remove your old mount.

Here’s where I SCREWED up:
I removed the mount the night before I was supposed to receive my new one from fcpgroton.com. The part never came until three days later (In fairness to fcp, it appears that UPS is to blame.) I left the two jacks under the car with the wheel off. I put a jack stand under the sub frame “in case” the jack failed. The car sat there for three days and I did not pay any attention to it, partially because I was too busy watching the Yankees loose to the Red Sox. Much to my horror I found that both jacks started to give way. The jack stand was holding up the car but the engine had now sunk below its normal height. It doesn’t appear that any immediate damage occurred (road tested ok) but I’m not sure about long term damage due to any strain that might have occurred.

I now had to raise the engine back up. The engine went up a little and then became somewhat stuck and I was worried about damaging the oil pan. I took a crow bar and raised the engine by placing the crowbar between the sub frame and the engine where the motor mount is. I then reached around with the other hand and raised the jack under the oil pan. I did this little by little to get the engine back up to the correct height to install the 14mm bolts.

First, install the 17mm bolts but keep them loose, there is a lot of play in them. Install the 14mm bolts next (don’t forget to remove the jack under the pan.) At this point I would recommend using the 12pt offset wrench to tighten the right 17mm bolt.

Hope this helps.