EMG has some active pickups but other than those all others are passive, so will slot right in to your current wiring.
Before you change anything you should, a) know what problem you're trying to solve, b ) have a good idea that what you are doing will solve that problem, and c) make the changes in such a way as to let you easily back them out if you discover you didn't fix the problem or caused a new one.
Don't bother with solder, as previously posted, use connectors, then all you'll need is a screwdriver.
Draw a diagram of which wire goes where on your current pickup so you can match them up on the new pickup.
Leave plenty of wire to work with.