Man...thats like tearing a page out of the bible and re-writing your own version and then sticking it back in...why one earth would you want to customize an Lp...You just dont do it, not only does it decrease value nine times outta ten, but it also messes with the perfection.
The only reason to commit such a crime would be to fix up an old, messed up Lp, or to re fret etc...If you do change pickups, make sure you keep the original ones, so that you can put them back in if you choose to sell that axe