towing a GMC 1500 2015

Is it 4WD? If so t-case in neutral and tow it 4 down.

2 wheel drive

Your 2WD choices are then: 1. On a trailer, or 2.Use a driveshaft disconnect system.

I( would normally refer you to the REMCO website, but it does not list the 2015 GMC, and does not have the 1500 listed as a 2014 model.
Therefore, I can only recommend that you read the Owners Manual under "Recreational Towing", if such a section exists.
If a driveshaft disconnect system is not available for that particular year and model, then you are quite possibly back to the trailer, or getting under it to remove the driveshaft from the differential yoke and tieing it up out of the way. I used to do that with a Datsun pickup, it isn't all THAT hard!

My truck is a 2014. I did a typo on the year.

I use a tranny lube pump on my 2013 Silverado. Only problem I have is my battery disconnect doesn't disconnect!!!! I've tried 4 Chevy forums and still don't have an answer. Still searching for an answer.

DICK