Freeze a Geemer on the bottom of the overhang just below the door to Final Missile Bombway. Freeze a second Geemer on the top left of its platform and setup a moonfall between them. Fall off the Geemers and clip into the tile left of the door. Press up to get out of crouch and lose the stored vertical speed (so that X-Ray works). Then turn-around, open the door, and go into the door transition as the third Geemer hits you. Falling off the frozen Geemers requires relatively high precision: This setup is a 4 frame window, not too far left, so you can get to the door transition, not too far right such that you enter the transition when falling.