My question is: What steps should I take next to ensure success, and how should I initiate the rental process? 

To take it a step further, you can do (or hire a VA) a process called skip tracing, to gather their phone numbers and emails.If you are driving for dollars, I like @Frank Procopio 's advice.

A local RE professional should be able to provide this information to you as well.In New York, we deal with this scenario frequently and oftentimes it does not make sense to legalize ADUs because the permit process is extremely lengthy, the cost is high (sometimes $150-300K for 1 ADU unit), and the potential increase in property valuable is not worth the risk.If you already have an approved permit/plan and can get your renovation down to $80K, you may want to consider this project if the ARV is say north of $800K.** You should also look into any potential property tax increases associated with this change.

Has anyone in the Philadelphia area done this successfully?

Absolutely, the success of this investment was greatly facilitated by a team of skilled real estate professionals.

Hey Matan, if you work with a solid investment focused agent, they can source you deals and connect you with the right team to be successful. 

Unfortunately I have a tenant moving out and am looking for guidance on the process of vetting out for a new tenant.

There are some LLCs in the city successfully using partition to buy properties at a fraction of fair market value. 

Hello all,I am in the process of acquiring a townhome near Waynesboro, PA. 

In my opinion, many traits that would make a successful real estate agent can translate to being a successful wholesaler.