Disassembly of the Desert Eagle is easy and can be accomplished without any special tools, though MRI does include a 5-in-1 tool to aid the shooter in the maintenance of its gun. Start by removing the magazine and clearing the chamber, then lower the hammer and then pull it back slightly until it clicks into the semi-cocked position. Move the safety catch into the “safe” position. Press the barrel lock pin on the left side of the frame while swinging the barrel lock on the other side counter-clockwise. Pull the barrel slightly forward to release it and lift the barrel out. Now draw the slide forward and remove it. Now the recoil spring unit can be removed. The recoil spring unit captures the gas piston, and once the springs are removed the gas piston can be removed for cleaning. This will also allow you to use the 5-in-1 tool to clean out the gas cylinder.
To reassemble, lay the slide upside down on a level surface. Insert the gas piston into place and make sure that the piston shaft recess is facing the slide recess. The recoil spring plate lug will capture this part. Using your thumb to keep these parts positioned, place the slide back on the frame. Now insert the barrel’s locking lug into the frame’s recess. Push against the barrel from the muzzle end and hold the barrel assembly against the frame while swinging the barrel-lock clockwise into its closed position. Check the pistol for proper operation by cocking and releasing the hammer and verify that the safety is functioning properly. There’s nothing fragile about the Desert Eagle—each of its components are machined from steel, robust in design and unlikely to fail.