ok, well this is all my fault really, but i need to know how to fix it.

i have a 1.3 mpi L felicia

I hit a rock while driving my car up the local forestry. The gearbox mount snapped in half and the engine basically fell out on that side.

anyways, the driveshaft came out too, and the gears were obviously stiff while the engine was slumped.

i fixed all that, the driveshaft, mount etc, but now it doesn't like 2nd, 4th, and reverse. all the gears that push into the gearbox, how do i fix that, i have a spare box, and well, a spare car. so what do i do? thanks guys

please note, i does go into gear, but it is stiff as hell. and very annoying.

you might have bent the gear selector rod. it might be worth checking that the gear lever housing hasn't been pushed backwards slightly, if you undo the bolts then push the whole gear lever assembly forward a bit the re-tighten the bolts. this happened on one of my felicia once when i went over a massive rock.