Check the diagram on Numrich website or in their book. egunparts.com The original manufacturer for your gun is High Standard model K2011.
www.savageparts.com has a schematic. I advise against disassembly unless you absolutely have to. sales@countrygunsmith.net
Send me your email I'll send you a scan of the manual.
Send me your email & I'll send you a copy of the manual.
Basic instructions can be found in the Citori Owners manual at the link below.
A Sears Moels 300 is a Winchester Model 1400. For a manual, go here: http://www.stevespages.com/page7b.htm For disassembly instructions, get a copy of Gun Digest Assembly/Disassembly for shotguns. Aslo, gunpartscorp.com has an on-line exploded diagram for the model 1400.
The owner's manual provides instructions for disassembly to the extent necessary to properly clean the shotgun. Replacement owner's manuals are available on the Remington web site.
If I were you, I'd pick up a Haynes or Chilton manual for the car. It will lead you step by step through the disassembly reassembly procedure. Trying to explain it here, cognitively is near impossible.
Get this book - The U.S. .30 Caliber Gas Operated Carbines: A Shop Manual" Book by Jerry Kuhnhausen It has, complete disassembly/reassembly, correct parts fit, repair and mechanical restoration, and a thorogh troubleshooting section.
Follow the instructions in the owner's manual. There are a series of Gun Digest books on assembly/disassembly of handguns and longuns you could also use.
Get your hands on an owner's manual (available from Ruger for free or eBay for a few bucks) which will have disassembly instructions or buy the Gun Digest Assembly/Disassembly volume for automatic pistols from the Gun Digest website. You can also go to Ruger's website and READ a Manual for the Mark I... http://ruger.com/Firearms/PDF/InstructionManuals/48.pdf
Please refer to the link below and choose the manual for the High Power pistol. There you will find instructions for disassembly and cleaning: http://www.browning.com/customerservice/ownersmanuals/index.asp
The first thing to do is get a good repair manual. All the instructions are in them. In my Haynes manual it says that after removing the caliper to place a thin piece of wood in the caliper then use low pressure (& they mean low pressure) air into the hose fitting to push out the piston. This procedure must be done carefully as you can damage the face of the piston if it is ejected rapidly into the metal parts of the caliper. One reason you need a manual is that all the other precautions & procedures for cleaning ,disassembly & reassembly are there. You should not do these procedures unless you have the tools & equipment & knowledge to do it properly.