Within the limits of action points available to you on your turn: at any time that you have one or more explorers on a temple tile, you may explore another level of the temple. You may do this a maximum of two times per temple per turn (though in this case you would need to have two explorers on that tile). You are free to move as many of the explorers as you like away from that tile at any time on your turn. If you have no explorers on a temple tile you may not explore it at all.
Okay, what confused me was that you have to retire all the members on the tile when placing a guard. So that made me think you had to keep all the required members that you've used so far and not let them move. Because, otherwise what's to keep you from moving all your members away and then using a guard? I guess essentially my question is if I explore 10 levels with however many members after I am done uncovering could I move everyone away if I wanted to?
There is nothing keeping you from moving all your explorers away and then leaving a guard... other than the fact that you can't leave a guard if you don't have more explorers there than any other player. If you are the only one on the tile, moving away all your explorers and then leaving a guard is a good play.