i have a 1998 chevy malibu v6 i have to replace the serpentine belt and the water pump, my questions are, do i have to reset timimng and is it hard and a long process to do.

It takes a couple hours if your hurrying a buddy of mine has a 98 malibu we had to put a water pump I can't remeber about the timing tho

do i have to take off the motor mount to put belt on

Yes and you put a jack underneath the motor to hold it up

thanks so much for your help

Serpentine belts don't take very long to put on once you figure out the routing. There is usually a diagram of the routing path some where under the hood. You don't have to take off anything, however you may need a special wrench or 1/2" drive ratchet to push the tensioner out of the way while you slip it over the last pulley.