I'm doing my first 3 tier cake. I had it covered and stacked today I noticed the bottom tier is sinking a bit. I have dowels in obviously not enough. I want to take the fondant off and fix it. Is there anyway to use the same fondant that's already on the bottom tier im out of fondant. Will the decorators icing work back into the fondant if I work it again and reroll it out?

Thanks for the quick reply I'm going to give it a try

Are your upper two tiers each on a cardboard?  If not, they must be or the dowels will do no good.