how many are there? where is the transmission mount on an automatic 1.5 motor? where are the mounts located? how do I replace them?

there are four mounts on a 88-91 civic front lower, rear middle, 2 sides.. the motor wont fall out if you replace 1 at a time, or even 2, probably even 3.
choose wisely.... u can do it

yea it wont fall out, when i had my d, i broke the trans mount, front mount and rear mount, i drove an hour home with a ratchet stap holding it in youll be ok, very simple

Ineptly called "motor mounts", only one of them is actually attached to the engine.

That would be driver's side, right in front of the strut tower.

The other three locate the transmission, and they are:

Pass front, bolted to front cross-member
Pass rear, bolted to rear cross-member
Pass side, bolted to pass frame rail area, just fore of strut tower.

The front trans mount is difficult to get out if you can't move the trans into a slightly crooked position, so loosen all 4 mounts (do not remove, loosen) to give yourself some "wiggle room".