Not TOO sure but when cars don't want to go into reverse, you need to put the handbrake on (if you're on a slope), let go of the clutch then push it all the way down in one fluent motion, while staying in neautral. Then try going to reverse, should do it just fine. Stiff gears are probably from just dirt and dust building up in the mech. Just take the rubber flap thingy off and clean underneath. Hope this helps!
James, March 2011