So I have narrowed down my problems to a bad rear passenger wheel cylindar!

Can anyone give me any advice before i attempt to change this part?

 

First see if the fitting where the brake line connects to the wheel cylinder will turn without turning the brake line. Sometimes the nut is rusted to the brake line so when you unscrew the nut it twists the brake line. If so you will need to get a new brake line to replace it with. Don't let the master cylinder run out of fluid while you are working as fluid will come out when you have the line disconnected.

 

Spray it with penetrating oil a few times a day for a few days before you attempt to break it loose.