You said you haven't soldered in a long time. I highly recommend you do some practicing on scrap wire etc first.
And take pictures of the insides of your bass, just in case you forget where everything goes, or if you want to return it back to normal.
Don't throw away your old pickups immediately, just in case you don't like your new ones.
Place paper or a plastic bag over your entire bass, solder can spit and drip.
Dont hold your iron on components for too long, you may ruin them on the inside. I've done that with a pot and 2 capacitors before.
Thats about all I can provide. Good luck.