I started a thread in the tech forum a while ago with soldering tips.
It's not hard to replace pickups, but leave yourself lots of time to do it, don't rush it. Try to find someone who knows how to solder to show you the first basics. It really isn't hard, but you don't want to mess it up.
Take a photo of the wiring before you start removing anything, that way you can at least get back to your starting point if it all goes wrong. You are unlikely to cause any damage by mis wiring (currents are too low). But you can 'cook' a pot if it gets too hot (it will get hot anyway) so try to get those solders on smoothly.
Use a good soldering iron, your standard cheap 'pens' are usually not hot enough to work well with the large mass of a pot. You can use them, but it makes the job harder.