When the vehicle has air suspension, switch it to the off mode. Set the car on jackstands, safely supporting it as you lift it. Unshift into Neutral and take off the handbrake while holding back the wheels with blocks. Before removing the driveshaft, you must carefully mark how it connects to the differential pinion flange. This marking enables us to realign the driveshaft's balance with the existing pinion flange when we reinstall it later. We use a scribe, hammer and punch, or paint to make the marks. Take out the bolts holding the rear universal joint. To keep the driveshaft from spinning, stick a screwdriver through its hole before loosening all 4 bolts connecting the U-joint to the pinion flange. When the bolts are difficult to reach, spin the drive shaft (or wheels) to find the best angle. Before you take out the driveshaft on models with two-piece driveshafts, take away the screws holding the center bearing support brackets. Pull down the back of the driveshaft, scoop out the slip yoke from the front end, and take off the entire driveshaft unit. Before taking out the driveshaft, slip a plastic bag over the transmission or transfer case extension housing, secure it with a rubber band, and keep it this way to stop fluid from dripping and protect from dirt. When you take out the driveshaft, stop and check both the extension housing seal and the differential pinion seal. If they need replacing, do that now. When you have a split driveshaft, take time to look for any issues affecting your center bearing. First, put the center bearing and bracket back in place on your two-piece driveshaft before fixing the two ends together again. When you took off the old extension housing seal, it's time to install a brand new one. Clean both the transmission and transfer case extension housing parts with the plastic bag removed. Place the drive shaft's front slip yoke carefully onto the end of the transmission or transfer case output shaft, making sure you avoid damaging the shaft seal's rim. Just put the rear end of the driveshaft and the center bearing assembly into place, fasten the support bracket bolts, and make them tight. Position the rear of the driveshaft overtop the vehicle alignment marks. When the marks don't match, spin the rear wheels until everything lines up with the pinion flange. Lower the car after you've checked and kneaded all bolts. Take out your jackstands. Bring back the air suspension system working if your vehicle has it.