Pulling the valve core could cause problems, I've seen many broken tpms sensor stems because of it(steel core,aluminum tpms dont mix)...Also seen many damaged seals on the core, resulting in a leak.

Best thing is to get a "tire deflator" screw it on like the valve stem cap, and it releases the air, no chance to damage core, seals, tpms...

They have adjustable 1's too just for the offroad purpose..

ADJUSTABLE TIRE DEFLATOR KIT From 6-30psi SET OF 4

You can getem cheap on Da'bay..

 

One more thing to add that I did not see anybody mention.. You should pull the airbag fuse also, that way the airbags do not deploy accidentally... Look in your manual at the fuse box illustration to find which one it is.. Pull it and remember to replace it when you are done.. I was just there last weekend and will post up some pics.. Enjoy...