I've personally have open the Note 8 and know that you can buy a replacement seal and Back glass and it'll cost you less than $15. It's only 10 screws to get to the battery after you use a heat pad to remove the back glass it's easy if you have a heat pad or heat gun or hair dryer you just need a lot of guitar picks or credit cards to slide underneath the edges all around it. P.S. the fingerprint scanner connector is on the right side of it and the camera lens cover assembly and that comes off with the rear glass as one piece.
So I actually fixed this myself. Out of desperation and exhausting every other option I finally just took the back glass off with the help of the teardown guide and "defibulated" the battery back to life. So the process went like this; after actually getting to the battery, cut an old USB cord and splice it down to the red and black wires leaving a few millimeters exposed and get an old USB charger, I used an old Samsung I had, A NEWER CHARGER INCLUDING THE NOTE 8 CHARGER WILL NOT WORK ex." fast chargers, QC 2.0 and QC 3.0+" ect. The ribbon cord leading off the battery are labeled "1 2 and 7 8" on the other side says which pair are + & - and very carefully hold the red to + and black to - for about a minute. Reconnect battery and plug the actual Note 8 charger in and Viola! You should be charging!!!! My back glass was already broke and is only $12 to replace. But I feel like if it wasn't cracked I could have done without damage...other then the paint coming off the inside a little bit.