Question dealing with Xenia, Brown Zoas, and Brown Mushrooms

Hello Everyone, sorry I haven't been around much but I have a few questions and am not sure where to turn. When I started in this hobby, the first coral I bought was a Xenia (big mistake). It has gone crazy and covered the rock it came on, plus it detaches and tries to spread. I also have some brown zoas and mushrooms that hitched on some live rock from the LFS. I recently upgraded my sump and have some room in there, but I was wondering If I take the rocks from my display that have these corals I don't really want on them and sump them will the corals just die down there without spreading to up to the display? Ideally then I could buy dry rock and replace the removed rock in my tank. Would I need to worry about a cycle with the dry rock? I could add it slowly over a week or 2. I just dont want to have to trash the rocks and the filtration. I have tried manually removing, and Kalk paste (im worried about my alk too). I just need the room to place nicer corals I can finally afford. Has anyone sumped these problem corals before?
They will just spread there too. I have coral that haven't seen light in 2 1/2 years and they are still very much alive. The only thing you can do is remove the problem.
I will manually remove the xenia then and the mushrooms, but I would rather not mess with the zoas. I'll probably toss the two rocks they are on and replace with some dry rock. Thanks for your advice.
I really try to get folks to get a little better corals. Here's a beginner mistake, I paid 45 bucks for pulsing xenia 3 years ago starting out. I now give away high end sps because that grows non stop.