Well congrats on the ootheca. You will need to let the ooth harden at least 24 hours so it is not damaged, before you do anything, if it was recently laid. Other than that simply clean as you would normally.
If you haven't cleaned her habitat before, the easiest method is to transfer her to a container, clean her habitat, and then return her to it. The ooth once hardened will be okay, I just would leave the ooth and stick it is on alone.