CAM seal replacement

You do need to set the timing at TDC, check all alignment marks and use a paint pen to double up so you are sure all is correct. Remove timing belt and cam shaft drive, pry out and replace seal, lube seal surface with engine oil so it is not running dry, replace cam gear and timing belt and re check all timing marks are still aligned before turning engine. Ring your supplier and double check the part number, cam and crank seals can be very similar is size so best to double check first.