If you can't do it yourself, having someone within driving distance to receive packages, assemble, get the wifi set up, label remotes or light switches, make the kitchen functional, change out your door locks or put cameras up, etc, as well as the decorating and making the place comfortable and appealing for your guests is a must.

Have it delivered to the house as close to same day as possible and hire a local handyman to put it in the house and assemble it.

I really didn’t need to know how to do anything going in, it was enough to know that I would have to assemble a kitchen cabinet, and that I would learn when it was time.

He knows the assemblies and how to treat the top of the walls as well (if not, will severely diminish the common double gyp-rock approach)Now, before you shake your head, here is how he would approach to hit 55+ STC.

They aren't people persons, they don't do any repairs themselves, they don't understand construction, and they don't assemble a low cost, local team they can rely on to help them when needed.  

And best of all, because of this reason, I’ve never had an issue with collecting rents or vacancies thanks to the location.It really comes down to the location, the team you assemble and your research. 

How did you assemble a team?

I personally would look for value add opportunities so you can either pull cash back out when done with the repairs to keep the assembly line moving.

@Jeff Jenkins  - in French there is a distinction between education and instruction: the first you receive at home (home including your neighbourhood / society), the second being what you receive in school.In both your country and mine, the school system - post secondary included - has, more-or-less, morphed into an assembly line to turn out cogs and consumers.  

I am weighing the pros and cons of different size DADU buildings as well as pre fab units that are assembled on location versus traditional building methods.