Yes, but it can be very tricky, as you have a "hotdog" shaped plastic tab that the turret slots onto and locks onto it by turning it around to face the front. It's hard to explain, but once you get it off, it makes sense.
http://www.transformerland.com/image...6/IMG_0806.JPG
If you are trying to get it off, turn the tank turret 90 degrees so that it's barrel is facing to one side instead of the front, and wiggle it around a little to see if it pops off. If that doesn't work, keep rotating the turret clockwise or anti-clockwise with constant careful wiggling, as the plastic tab may have moved off its 90 degree setting (it is just screwed in, and the screw can move if someone was rough with the tank turret... like with my first Blitzwing as a kid).