The goal of a large number of real estate investors is to have a large enough real estate portfolio generating a large enough amount of cash income to retire from whatever their “8 - 5” is, be that corporate employee, independent contractor, or business owner.  

You'll also want to prepare a personal financial statement for each of the guarantors/owners of the entity, the entity documentation, 2-3 months worth of bank and brokerage statements for each guarantor and the entity itself, any plans, specs, etc for the property, information on your GC, and a detailed Scope of Work from your contractor along with the draw schedules they expect.

Contractors win.

You can try to outsource that experience to general contractors, property managers, agents, and others (I highly suggest you do), but all of those services will eat into the last "R" of repeat. 

Should I begin by looking for a contractor?

Very unhappy with this PM (I already took over handling maintenance because of the ridiculous amounts they were agreeing to pay contractors) and won't be using them moving forward, but was hoping to keep them on to handle the eviction.  

Does anyone know how to transfer the registration? 

I would probably try to speak with them face-to-face or on the phone and finish the conversation by telling them you will send them a formal letter shortly with the exact date after you talk with your contractor/partner, etc. 

The BRRRR combines all the things that can go wrong with rehab and managing contractors with the holding costs during the time when the rental is being seasoned, and then you are literally at the mercy of lenders who may or may not refinance you at a rate that will allow you to cash flow.

Other contractors hired to look at the property are saying something was not done correctly.