subframe mounts

have 96 taurus. my front subframe mounts are starting to clunk a little. can they be replaced easily by a diy'er or does a shop have to do it? how bad would they have to get before it would cause your engine to fall out?

I have a 98 Taurus that needed the subframe bushings replaced. It cost about $100 to have it done. I also ended up needing the forward subframe bushings replaced as well. The engine would rotate a little on acceleration and I would hear a thump. There were some recalls out for the subframe bushings if I recall but it didn't include my 98, it might include yours though. Wouldn't hurt to check.