Wow, that's incredibly inconvenient as a way to be stuck. Leareth is going to need some help from an assistant to get them out of the setups as needed once the demorphing starts, since he'll be occupied watching the side of it in z-space.
He explains the protocol. It'll take him about an hour of work, during which time he wants to be in a room alone with Cayaldwin, who's observing and helping out, and the Andalite in question, and for them to stay very still and not distract him. He'll warn them when everything is ready before triggering the demorph. The process seems quite safe and reliable, he's done another two dozen iterations on larger animals than rabbits to make sure his new power-supply setup would be sufficient, and all of them seemed fine. That being said, he of course can't promise that it'll work, and the worst possible outcome is that they die in the process. He thinks that's very very unlikely but they should know what they're agreeing to.
Leareth will stay with the demorphee for a couple of hours afterward, in Andalite morph, because he wants to monitor for side effects subtle enough that he didn't catch them the first time, and also they're likely to be unused to their Andalite bodies and find the first little while quite disconcerting. Their first test case was fine within a day, but he's guessing a lot of them have been trapped far longer than a month.
Questions?