how can i fix my rear handbrake sticking vauxhaull vectra 1.9 ?

You dont say what year the car is, yours may be different from mine.
Have a look at the back of the wheel, you should see where the handbrake cable hooks on to a lever, there should be a return spring on it. Check the other side to compare. Replace if missing.
If it's not that then the brake will have to be stripped and cleaned.

epsilon
September 2009