You will need some special service tools for these repairs. Volvo special service tool #999 5456 and #999 5433 are used for the timing belt replacement. You will also need new screws for the damper-to-crankshaft sprocket when reinstalling the timing belt. For the rear main seal replacement you will need special service tool #999 5651. You must remove the flexplate or flywheel, clutch (if equipped), and transmission to replace the rear seal. To replace the front crankshaft seal you need special tool #999 5304 as well as #999 5919. You remove the timing belt then remove the crankshaft pulley to access and replace the seal. You will need clean engine oil to lubricate the seal mating surfaces. If you need further info. For these repairs just let me know.