Motor Mounts

This might be a dumb question. I tried searching for a replacement forum for motor mounts. My engine is not as stable as it was when it was new, there are slight (not violent) shutters that i can feel when sitting still at stop lights and warm-up. I was just wondering how hard it would be to replace motor mounts. Does the engine have to come out or will the other mounts hold while im replacing the other and do them one at a time. Im a little thick when it comes to this sort of stuff and am in no shape tool-wise to remove/ lift the engine. I did read a little about filling the mounts with poly bushings or something like that and I don't know which would be more beneficial. Other than a plugs and wires tune-up which I have decided I will be doing a DIY for this website, this is something that I was thinking of putting on my to-do list, if it seems necessary. thanks
JR

I just did all three mounts on a 2004 with 210,000 km on it.

You will need a jack to support the weight of the engine while doing the motor mounts, and if you go one at a time, the engine will not go anywhere. The transmission support is easy - just remove and replace, no need for a jack or to support anything.

No idea on the urethane, I just left them as is.

you most likelt only need a dogbone, but a few members here have torn the tranny mount and engine mount.

if you want, inspect the engine and tranny mount for tears, if the appear ok, pull the dogbone and fill the mount with urethane to stiffen it, windsheild urethane will be sufficient, but if the mount is badly damaged. buy a new one and fill it.

Awesome!, thanks to both of you for your replies. I just had my mechanic friend look at it and he said i should be good for a long while since i dont drive the car too hard and that maybe im just a bit paranoid. my uncle's miata just broke down and he is thinking of selling it so I would like to try and save as much money as I can so i can buy it off of him!!!! Thanks again!