The pump is not real hard to do, but the damn balancer has to come off and that is torqued to 275 ft lbs. They make a special tool to hold the engine from turning, or you can remove the starter to hold the flywheel, so you can loosen and then later tighten it.
You may need a power drink to help. The cost to have someone do it is, $600--- $1,000!
Chevy 04.5 LLY, 2X, shell, XDR, MikeL Heavy duty up-grade, 6spd, TransGo, deep pan, de-badged, 65 Gallon replacement Aero tank, LBZ-mp, Kennedy pump, shimmed, Pre-fuel filter, tow mirrors, BU cam, gauges, GPS, Sirius, bags, custom grille, fender vents, HD trans cooler- Curt front hitch, footwell lights, load lights, Studs, head gaskets.