If you have enough liverock in your tank, then you can just remove the bioballs and use your wetdry as your sump/refugium. If not, then you will have to slowly replace the bioballs with more liverock. Your bioballs and your liverock contain your bacteria which is beneficial to the survival of your tank. If you dont have enough liverock and you remove all of your bioballs at once, you could possibly start another cycle. If it were my tank, I would maybe remove a handful of bioballs a week, until they are all out. This would give the liverock time to regain more bacteria.