I need to replace the wheelcyliders. what should i do

you will probably have an issue when you try and unscrew the brake line from the cylinder. I would spray PB blaster on the fitting and let it sit. there will be a spring that holds the shoes together. take the spring off. on the back of the cylinder there will be 2 bolts holding it in. (remove bolts) disconnect line, remove cylinder. I would use some vise grips to pinch off the rubber line so it does not drip all over. reverse procedure. I like to screw the line in before i bolt the cylinder in. When done have some one pump up and hold pressure on the line. Open the bleeder and then close it before the pedal is released do it 3 times each side (do not forget to remove pinched pliers that are on the hoses first)