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http://www.pontiacbonnevilleclub.com/forum/viewtopic.php?t=42273
0) Remove the torx screw holding the airbox to the front fender. This may have already come loose on most cars when the busted trans mount flops the powertrain around.
1) Raise and safely support car - not via the subframe - stands at the jack points at the rockers are ideal. You want to go pretty high. Don't forget to chock your rear wheels and set your parking brake beforehand.
2) Remove the clips holding the front airdam. Don't force them out, pry up the center section of the clip and they will just slide out.
3) Optional: Remove the front wheels. Recommended if you don't have an impact extension and air tools.
4) Support the engine/transmission with a jack. I use a bracket covering the exhaust between the oil pan and transmission pan. It'll be pretty hard to miss.
5) Unbolt rear half of the front trans mount, there are three or four locations: Bottom nut under the subframe, two nuts near the exhaust manifold that hold the bracket, and two studs that are bolted into the transmission. There is also a secondary bracket/bar that will need to be moved out of the way.
6) Undo the bolts for the two side engine mounts - they are near each wheel. If you pulled your wheels, you'll have lots of room. If not, you may be able to cheat and access them by steering the wheels to one side.
7) Undo the front two bolts for your subframe. You may want to use a jack (I use a spare tire jack) to ease the subframe down. Air tools may come in handy here to break loose the thread lock compound.
8) At this point the front mount should be loose and flopping around - here comes the challenging part.
9) Slinky the mount AND bracket assembly out from the engine bay. You may have to pry downward on your subframe to create enough space, OR jack up the engine/transmission to create enough clearance between the body and subframe. Play around here. I find a good place to pry would be off the AC compressor. Be careful about the metal lines (oil? fuel? ABS? I forget) that pass through this area. You will have to move them around, but make sure not to pinch or break them. I have found the best way to take it out is by turning the whole assembly upside down so that the bracket comes out first.
10) Cuss, swear, and take a break. Have a beer or six.
11) Hopefully you'll get the mount out. Installation is pretty much the reverse of removal. You may want to put some new thread locker on the subframe bolts.
You are probably doing no favours to your back 4 front subframe mounting points or your AC compressor by doing it this way, but I find it's the most effective for doing the front mount.