This will allow you to remove the person and do the financing on your own.Home Equity Loan/Line of Credit: Since you're looking to access equity, a home equity loan or line of credit (HELOC) can be a good option.

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

Although I've considered a future line of credit against the property as my best long term option, I would need to pay down the remaining balance first.

Instead, you could explore pulling equity out through a home equity line of credit (HELOC) or a cash-out refinance.

A couple issues with Credit/income on paper.

.: Quote from @Jay Hinrichs: when I was buying notes I did not even run credit.. but I only paid 10 to 20 cents on the dollar.  

At it's basic level:Assumption: Asking the bank to turn the loan over to you and going through the normal underwriting process, credit, income, DTI ratio etc SubTo: Taking over the loan without telling the bank, no underwriting, no credit check, no income verificationBoth have risks, but it's not my intent to be detailed in this post.

This allows entry without a key, and allows me to change the lock as needed if I don't want someone in there.As an agent, I provide contacts to my clients who will do these things, and occasionally I will do favors for past clients who need someone to open the door or quickly supervise an appointment; of course not all agents will do this or for free.  

You can go up to 6.75% and get 1 point credit towards the broker fee. 

Quote from @Zach Edelman: If you do a DSCR loan and vest it in an entity - you and your partner can both PG the note and it will report to neither of your credit reports, thus having no impact on your DTI!