how hard is it to change out the nozzles. i know ill need to have them pop tested after the change.

 

Not terribly hard. Hold the body in a vice with soft grips, then use a wrench to thread the tip off. I'm not sure of the exact torque though. When they get pop tested, and need to be adjusted, they have to be disassembled anyway. May be easier to let the diesel shop do it all.

 

inmho your better off to buy a complete new injector and get a matched set

 

but doesnt pop testing them make them all the same?

 

Pop testing is the amount of pressure that is needed for the injector to open.