There is a small amount of adhesive on the bottom side of the battery along the edges. Start at the bottom of the battery breaking the seal and work your way up along both sides at the same time. Came out clean and with minimal effort.
Be mindful of the volume/power button cable on the top left. Safe that corner for last, sliding the battery out from under that cable.
I just tore into my Verizon M9 to replace the battery and there is no adhesive between the battery and motherboard. There is some adhesive on the bottom of the motherboard between the board and the bottom speaker housing but that was easily overcome by gliding a metal spudger under the bottom of the board between the board and speaker to break the adhesive bond. Board lifted out without a problem after that.