It's an MO5D transmission and your symptoms sound like a bad slave cylinder (remove transmission, replace slave cylinder, install transmission). It could also be a bad Clutch Master Cylinder, which is easier to replace, but harder to bleed (invert it from its normally mounted position).
If you go to all the trouble to remove the transmission to replace the slave cylinder, you should install a new clutch at that time. A new flywheel is recommended too (some say to resurface the old one, but that costs 1/2 as much as a new one).
I picked up a 93 2.3 real cheap because its "transmission was bad". I found the transmission was empty (no ATF fluid drained out, just metallic sludge). I flushed it, refilled it and installed a new slave cylinder and drove it for several months (yeah, it whined). It finally did fail (stripped its internal gears). Long story short, check your transmission fluid level!!! It uses Mercon ATF by the way, not gear oil. Reason I say all this is, some have said bad synchros will make it hard to get in gear/shift. Well, synchros need fluid......if yours is empty/low, you have a leak, either the shifter bushing plugs or at the rear driveshaft seal ($8 part, easy replacement).
But if its full of ATF, I'd guess "bad slave", very common.
