Beamhead's method is one way to get the clip off, but it didn't seem to work for me.
Since I have had "complete" success removing the pocket clips from my L1, L4, and E1e lights several times, I wish to share my removal method with those of you who have had no success.
<font color="red">WARNING:
Removing the clip may have a negative effect on the upper o-ring. When the clip is on the body, the clip's plastic wedge stops the o-ring from being squeezed into the body's clip groove when the bezel is tightened. When the clip/wedge are removed, and the bezel is tightened hard enough, the o-ring may be damaged as a result of it being pressed into the body groove. To protect the o-ring from being damaged by the edges of the groove, you may want to find something to wedge into the body groove by itself, which will stop any portion of the o-ring from being pressed into it. I have yet to find such an item. When I do, I will share it in a post.</font>
If you still want to remove the clip, follow these steps.....
Remove the bezel, then the o-ring. Attach a strong string to the clip at the end where it is attached, doubling it over. Wrap the string around my palm a few times so as not to have it "bite" into my skin. Position the pocket clip so that it is not facing the inside of your hand, to avoid having the clip slice you if it slips. Give a "strong and sharp yank" toward the top of the body, while holding the body in the other hand very securely. The clip and the plastic wedge will slide up and away from the body groove together. To reattach the clip, position the plastic wedge on the clip, aligning it so that it's flared out section is in line with the flared out section on the groove on the body. Slowly press in both parts as a single unit with a hard blunt object, a screwdriver, or the tip of pliers. No banging is required, just a sliding action.
Let me know how this works for you!