Joint venture, one party goes to jail

Hello, So in 2015 my friends enter in a joint venture agreement for sale of property to renovate and flip this 4plex. The agreement is between friend 1 and friend 2 is to put money upfront as friend 3 facilitated the deal and was going to bring in his expertise and take care of the rest. Along with that he got a limited power of attorney along with a quitclaim deed from the owners. Friend 3 will be unable to fulfill his part of the deal. 1. How can they separate themselves from friend 3. What would be the next step? Thank you,