How do I change a rear axle for a 1988 Porsche 911?

There are six bolts at each end of each axle. Put the car on jack stands so that the wheels are handing down and you are able to rotate the wheel. From underneath the car, have a helper apply the brakes as you loosen the bolts one at a time. There are also roll pins or shear pins that may hold the CV joint to the transmission and to the axle stub. Jiggle the axle a little and it will come loose. Clean the bolts and use loctite on the bolts and torque them with the assistance of your helper. The helper works better than trying to use the parking brake or the engine to hold the axle from turning while removing and installing the bolts

Somtimes old cars have diffrent axels so it will be hard

take it out