A litle help please with my vandoncid

[Swamper]

I have a Vanda hanging on the outside wall next to an Oncidium of some sort. They have been happy next to each other for at least a year now maybe two. I looked at the Onc. and thought it might be time to repot it. I noticed when I tried to bring the Onc down that the vanda has made a home or at least has grown attached to the Onc. I need to break this up so I can repot?!? I am thinking if I wet the heck out of it, it will slip out easily.Am I right? Im a little bit afraid of doing some damage to either. Any tips would be greatly appreciated.