How to Proceed with Evicting Tenant (Family Member)?

[Ayodeji Kuponiyi]

My wife has power of attorney over her parents house in Philly. They recently moved back to the Caribbeans and rented out their home to a family member. The cousin paid first and security and has yet to pay the April rent. The family member (cousin) has even gone far as to demand paying $40 less due to receiving transfer fee from wiring the rent from her bank to my in laws bank. My in laws gave her the bank account and locations within the area for her to make rent deposit but it seems the cousin has their own agenda. We recently found out that the cousin even changed the locks of the house and hasn't given us a copy of the key when we asked for one. Eviction is clearly the next step but what are your thoughts and advice fellow BPers?