Side screw is to get the ground to the pcb, doesn't attach to the top cap.
Loosen the screw in the top cap just a little, then unscrew the top cap. You might want to use one of those little rubber jar openers to improve grip on it.
Once the cap starts unscrewing be gentle, a wire comes up to the center, so don't pull it away.
The pcb ground wire, what that side screw attached to, should just be sitting there, as well the little nut that the screw is actually held on by.
Me, I would disconnect the top positive wire, make sure to see the order things are attached. Note that the top screw has a little black washer - when you put it back together make sure to use the washer. Note the order of parts on the back side of the cap, too.
If there is obvious liquid leakage, clean the yup cap and grounds screw holes with a qtip soaked in isopropyl alcohol.
Next, reattach the ground wire, using the side screw and nut.
Next, reattach the positive lead to the top cap. Remember to include the washer on the top screw. Don't tighten it too much yet, you want some play when you screw the cap on.
Next, screw the top cap on. Me, I use just a bit of loktite blue 242, available at home depot or other hardware stores. A dab on the threads, screw the cap on, wipe any excess off.
Finally, tighten the top screw, snug but don't crank on it.
(i am pretty sure the above is correct. You can also look here for the thread on buzz top cap replacement.)
Alternately, send it in
