Just bought a 1998 Chevy 1/2 ton pickup from a guy at work.  It has the V6
engine.  The electric fuel pump on this truck is very, very noisy - sort of
a high pitched whine.  Anyone familiar with this problem?  Does the fuel
pump need replaced or is this caused by something else?  I was just looking
at some parts store web sites and I see a new pump is around $300.  I would
really like to get rid of the noise.

The guy I bought the truck from gave me a Haynes manual and it says to
relieve the pressure on the system you have to have a fuel pressure gauge,
etc.  Used to be the manuals just said to unhook the electrical connection
to the pump and run the engine until it dies to relieve the pressure.  Is
replacing the fuel pump anything I can do myself or am I better off taking
it to a professional?  I figure by the time I pay retail price and labor it
will be $500 or more but if that what it takes I supposed I have no choice.
Any info is appreciated.