attaching pickup covers...?

to attach a pickup cover to a humbucker..do i just slide it on top the uncovered humbucker..or something?
i've read that in some cases you do, and in other cases, you need to re-wax pot the pickup, or do something far more complicated

which one is it? how do i properly attach a nickel humbucker cover?

some other people told me that i need to put electrical tape on the baseplate or something. i also heard that i need to turn the cover to the bottom, and solder along the bottom edges
any and all help is needed and appreciated (pics too!)

thanks alot!