Removing / Rebalancing new nodes

Hello. I am trying to add 3 nodes to my existing Membase instance. They get to about 33% rebalancing and then hang. Also, if I try to remove them, they remove all active keys, keep a small amount of replica keys and then hangs again at 22% on the 3 nodes I want to remove. I have tried stopping/starting membase-server on these instances, and stopping/starting the rebalancing (and waiting 5 minutes + between operations) but nothing seems to be able to go - I have no problems destroying these 3 nodes, but I need to keep the data in the production membase intact and up, what is the easiest way to yank them at this point so that I do not have an interruption in the 'good' servers?

Thanks