I'm also curious on how to run the beta client on a jailbroken device. My question is legit, but don't answer if it shouldn't be answered

I have an official access to the beta programme on my old iPhone 4, but recently got a new iPhone 5, so I can either run both devices at the same time with different accounts, or try the new jailbreak stuff for the iphone 5 and try to run the beta there, but unless I know it's possible and easy and won't break anything, I'll probably won't even jailbreak my device.
How do (did) you do it?