I have a 96 silverado c1500 the low pressure switch and high pressure switch on my truck they just unscrew and have a Schrader valve behind them so. No problem removing them. Just unscrew and screw the new ones on. Plug and play.That's what I thought too. But I've found several threads like this:
http://www.fullsizechevy.com/forum/arch ... 61932.html
I can never seem to narrow down a year...this thread seems to be talking about an 03.