FisterD

That's what I did. Remove the valve stem and crank it down. It's pretty easy, like others have said.

Edgy01

Once you remove the valve core they collapse extremely well. They were designed to do just that. What I suggest you do after you inflate it and fully wash it off is you dry it and then using liberal amounts of baby powder, smother it with that stuff. The talc helps promote longevity in rubber. I wouldn't wipe off that much of it either as you deflate it. Then store it back in the trunk. I use that stuff on the rubber door seals as well particularly if you are in an area prone to freezing temps in the winter.