1. First, remove the magazine. Grasp the gun in your right hand, with your left hand run the slide back and lock it open with the safety lever. 2. If the weapon's breechbolt does not readily rotate clockwise (when looking forward over the rear sight) in this position, the weapon is likely varnished shut from hardening oil.
If varnished ... soak the whole gun in WD40 or Sheath or other gun solvent for 2-3 days. It will loosen the varnished oil enough to get everything apart. If after 2 days of soaking it will not turn a full 90-degrees clockwise, place a strip of leather around the breechbolt and turn firmly with a pair of WELL-PADDED pliers. (Makes me cringe to use the word pliers and pistol in the same paragraph, but 90 years of crud sometimes makes it necessary.) After it gets loose enough to disassemble ...
Now, again holding the gun in the right hand run the slide back with your left. Lock the slide back in place. 3. Grasp the bottom of the extended breechblock with your right thumb and the top of the hammer with your right forefinger. The block should rotate freely about 1/8 turn to the right. Now The Grand Savage Secret: SQUEEZE the hammer between thumb and forefinger to depress it against the block while rotating a full 90 degrees clockwise. Pull the breechblock straight back and out.
4. Next, depress and hold the trigger while releasing the safety lever and running the slide off the frame. The barrel is free floating and will fall from the locking lug if you aren't watching for it. 5.Take a brass wire brush and scrub down everything to remove the varnish ... even on the barrel and particularly behind the extractor. Even brush the springs. The cleaner it is, the better it will shoot.
If it is visibly still dirty inside the breechbolt assembly, click HERE for detailed pictorial instructions on further detailed disassembly requiring tools.