The rear shock is giving me problems, the nut is turning along with the piston. I did one side already , the nut removed easily, however i couldn't put the nut back on , so i used a different one. The original piston rod nut has some sort of plastic on the thread and when i try to screw it back on the piston rod, it turns with the nut. Any ideas on how to resolve this.

 

That's probably a nylon locknut you're talking about. Grab the piston with something non-scratching (rubber covers for pliers for intance) and hold the piston from spinning. I'm guessing you're using hand tools on the nut too.

 

Yup, when we swapped out my struts we did just like what Bejay said.... used pliers to hold the piston (we actually just gripped it around the dustboot, which might be risky, since ya might actually rip the boot if its old)...

 

DO NOT use plier to grab the shock piston. DO NOT DO THIS !!! You will void the warranty. Just tighten as much as you could, make sure that the assembly is sturdy enough and put it on your car. Once you've let the car down (not on jack stand) the weight of the car will be able to stop the piston from moving. You can then tighten the nut easily.