Since you're in Nico now, I can point you to a service manual for getting that headliner dropped. That other site frowns upon even mentioning Nico Club, so I was kind of stuck trying to help you with specifics. Here's a link to the Interior manual for the '16, your '17 will be pretty much identical:
https://www.nicoclub.com/service-manual ... %2FINT.pdf
You need to remove the LUGGAGE SIDE UPPER FINISHER on both sides, and to do that you need to loosen (but not remove) the LUGGAGE SIDE LOWER FINISHERs. The tools you'll need are very limited, 10mm and 14mm sockets with a short extension and ratchet, plus a finesse tool (nylon prybar). See the stuff starting on page INT-33. Once the lowers are loose and the uppers removed, there are three clips and one 10mm screw holding the rear section of the headliner (see INT-32). With the back of the liner dropped, the connectors will be right there. It looks like a lot of work but it really isn't. With power tools it would take me about 20 minutes to expose the connectors, so figure 60~90 taking it apart for the first time using hand tools. Reassembly will be a lot faster, since you'll know how it all fits together.
If you want to learn all about the ABD system, it's in the Door & Lock section here:
https://www.nicoclub.com/service-manual ... %2FDLK.pdf