Try this, the RIA dissasembles differently from the normal 1911. A bit like the Charles Daly as I suspected. The search function is your friend!
Disassembly
The field stripping procedure to be followed with the RIA Tactical .45 ACP is different than for other, full length guide rod equipped full size 1911 type pistols. Making sure that the pistol is completely unloaded, and with the magazine removed, the slide must be moved to the rear (under tension from the recoil spring) so that the slide take-down notch is over the slide stop, at which time the right side of the slide stop pin is pushed, and the slide stop is removed. The slide is then moved forward, off the frame, taking care that the guide rod, recoil spring, and recoil spring plug remain in position with the slide. Allow the guide rod to move back slightly toward the rear of the barrel, so that the barrel bushing can be moved, carefully, clockwise, to release the recoil spring plug and spring, toward the muzzle. The recoil spring plug must be pushed in with a non-marring tool (such as the handle of a nylon toothbrush) in order to be able to turn the barrel bushing. Then the full length guide rod can be removed from the slide, toward the chamber end of the barrel. The barrel bushing is then moved counter-clockwise, lining up its notch with the recoil spring tunnel, and removing to the front. The barrel link can then be lowered onto the barrel, and the barrel can be removed from the slide, from back-to-front, toward the muzzle. (This rather complex disassembly procedure is required, because the FLGR is not compressible with the pistol in battery, or, with the slide slightly pushed to the rear.)
Here's a link to the entire article:
http://ezine.m1911.org/RIATactical.htm
