I have a schwinn prelude that I converted into a fixed gear bike. The bb, however, is making loud clunking noises. It came with the bike, so I am assuming that it is the original equipment.
I have a new bb (just the cups and bearings and lockring, no axle) How big of a project is it to switch it out? Should I take it to the lbs, or can I do it myself? If so, what tools will I need?

Also, what size bb does that bike require? I have a leftover splined bb and crank from another bike and I am wondering if that would fit.

thanks