If you can't remove rock, you're only option is to make the tank smaller (i.e. remove water or partition off the tank). Any way you do it, the quicker you do it the better for the inhabitants you're trying to catch and the others still in the tank.
I just caught out two dominoes the other day and I know that it is not easy (as it isn't for any fish that wants to stay where it is). I was due for a water change, so I took out water and that helps, but the rascals know how to use the rocks. I tried to keep them into one side of the tank. Time was an issue for me and I didn't want too much stress, so as a last resort I took out some rock.
I guess I didn't really help you out. Best of luck, I'll be cheering for you.