The Darth I had a while back, had a metal ring for a negative contact. This had two screws that held the driver in. Once this ring was removed, the driver could be levered out. Maybe the design has changed?
Does it look like this Review: Blackshadow Darth NW (3 x XM-L | 3 x 18650)?
Edit Glad you got it sorted, hope you get it working again 