Whether he is there or not doesnt matter because he is on the lease. Take him to small claims court for his portion of back rent, future rent and utilities. You can also add in court costs and you will win easily. If you do go after future rent and utilities you cannot kick him out or have the lease changed though. Which brings up additional issues. Do you really want to live with someone you ha to take to court? Do you want him to have access to your belongings?
My opinion, take him to court for back rent and utilities plus any court costs and any costs associated with either changing or breaking the lease. If you can still afford the condo, you can have his name removed from the lease. If you cannot afford the condo alone, then you can break the lease and find a new place.