You would need to spend a fair ammount of money on equipment, it would come to more than the worth your fridge.
You need a compressor to draw down a vacume, brazing equipment or crimping tools & refrigerent.
To tell if you if need a re gas feel the compressor , if it is very hot it could be you need re gas.
I sugest you find a local engineer to help you find the cause of your problem.
Engineer Peterborough Uk., September 2009