Turn off air suspension system if equipped. Raise vehicle on jackstands, place transmission in Neutral, block front wheels. Mark relationship between rear driveshaft and differential pinion flange. Remove rear universal joint bolts and center bearing support bracket bolts if applicable. Lower and remove rear driveshaft, protect extension housing. Inspect and replace seals if necessary. Check center bearing for two-piece driveshafts. Install in reverse, align marks, tighten bolts. For front driveshaft on 4WD models, remove shield, mark relationships, remove bolts, lower and remove driveshaft. Inspect and replace seals if needed. Install front end to front axle differential pinion flange, attach rear end to transfer case output shaft companion flange, secure shield. Remove jackstands, lower vehicle, reactivate air suspension if applicable.