Contour Enthusiasts Group Archives Forums Modifications Audio Question's about factory amp

I bought a new headunit & the place I bought it wanted to charge me $75 to bypass the amp. I asked what would be done to bypass the amp, & he said they needed to re-wire all of the speakers. So I asked if they were litteraly going to re-wire all of the speakers, or if they were going to use a plug adapter to bypass the amp. He said they would need to re-wire all of the speakers, but he wasn't sure how they did it. So I said no thanks to the amp bypass & scheduled the install for Feb.21st so I could check into bypassing the amp mylelf. After searching a little while I figured it would be easier to ask the experts directly. Any help you guys can give me would be greatly appreciated.

Here are the ?'s:

1)Why does everyone bypass &/or remove the factory amp?
2)How hard is it do yourself, & what would I need(tools/parts)?
3)Can I bypass/remove the amp after they install the stereo?

Oh yeah, I bought a Pioneer DEH-P4600MP.