Before you start, make sure the covers line up perfectly with the pole pieces on the Duncans. Gibson and Duncans vary a little.
1. Squeeze the covers on as tight as possible. It's best if you put some flux on the areas you plan to solder, so the solder sticks better. Once the covers are soldered firmly onto the pickups....
Step 2. Heat up a pan with Parafin Cooking Wax, which you can find at the grocery store in the baking section. I put a piece of cardboard on the bottom of the pan to keep the pickups from melting or pitting. Submerge the pickups, while holding the lead.
When the tiny air bubbles stop coming up, throw the pickup on a paper plate and into the refrigerator. If a little wax drains out, that's OK. Remove them from the fridge and wipe all the excess wax off the pickup.
Install into your guitar, and adjust the height.
If you don't pot the pickups, you'll likely have a microphonic problem where the guitar squeals on highgain settings.