[OCCRA]: drill transmission

[greencactus3]

our hand drill. which weve been using for a couple years, (exactly the same one we are using for this years robot) is starting to go bad i think... and im hoping someone can help us fix it maybe..
problem 1) the shifter is stuck in 3rd gear.. literally jammed.
problem 2) the clutch, even when its in the drill setting, slips quite easily. i can hold on with my hand, and in 3rd gear(well, cant test the others) i press the "throttle?" and the clutch goes....slips....

i have never actually looked at the clutch, and have no idea if its just starting to wear down or whatever... and the jammed 3rd gear... well i guess i should take the whole tranny apart? id rather ask first tho. as its still usable for light applications.
and i dont exactly know how the gear shifting thing works.... it switches by twisting parrallel to the axles(gears, the spinny part. not axle.. whaddya call it?) and not perpendicular as the ones were like last year...

anyone who can help us fix this would be greatly appreciated! thanks!