Invitrd roommate in to pay half rent but he hasn't. I live in Philadelphia what can I do to get him removed if he isn't on my lease?

You invited him as a sublet. There fore you are his landlord and he is your tenant. You follow the same rules for any tenant.

You give him a 10 day pay or quit notice to pay in full. If he doesn't pay by the deadline, you go to housing court and file for an eviction order.