After going through this process and seeing how messy the adhesive got for me (was unable to purchase the ifixit adhesive remove because it cant be shipped to Canada so I had to use Isopropyl Alcohol). I would recommend taking everything out. That in addition to if there are any sort of accidents at least you logic board etc are protected.
100% take the power connector out. This guide is amazing but that is something I would change in it. Also I would do step 35 before attempting to remove the logic board. Unsure if there are other implications of this approach.