The best front pulley puller I have found so far is for a Dodge and you can rent it at your local Autozone. Get a new water pump gaskets, front cover seal and gasket, and pulley bolt. I'd go one step further while you're that far down and drop the oil pan and swap out the oil pump. You can go with a ported LS6 pump or get the LH6 displacement on demand 5.3L engine high volume pump.