If I understand you right, I think I can just look at the current fan's red and black wires to get an idea of where the new one should go, then I won't have to guess. But I agree that just snipping the guides sounds like the way to go!
Thanks.
Try this one on for size: I think another culprit in my loud PC is the case fan. It is a 4U rackmount, and there are two fans on the front. One is an 80mm, the other looks to be a bit smaller, maybe a 60mm? Anyway, they are wired together to a single 4 pin PSU connector. Since I bought 10 of these cheap Panaflos, I'm thinking about replacing the 80mm fan with a Panaflo. Will i need to do some tricky stuff here, or should I just plug the new fan into a spare header on the mobo and not worry about hooking up the smaller fan? The smaller one looks like it was designed to cool a hard drive, because there is a 3.5" bay right next to it. I put the hard drive somewhere else so i might not need the small fan.
I know this isn't the clearest question, but I'm not currently looking at the computer so it's the best I can do.