Your JA22 is the same as Jennings j-22. On the back part of the slide, where you can see the firing pin when cocked, there is a peice of metal around the pin that is a clip holding the slide down to the frame. Remove the magazine, check to make sure it is not loaded, then use something to push the metal clip towards the front of the pistol. Lift on the back part of the slide while the clip is pushed in. Make sure to cup the back of the pistol with your hand or you will be looking for parts on the other side of the room.
Take it to a gunsmith and ask for help
Ask a gunsmith for help
There is no need to disassemble for routine cleaning.
Best to find a gunsmith and ask for help
Not recommended for normal cleaning. Seek the services of a gunsmith.
Best left to a trained gunsmith. For normal cleaning, no disassembly is needed.
If you have to run it with the choke after it has warmed up, you need to disassemble the carb for cleaning.
You can download or request a manual via mail from the S&W web site
Jimenez'
Ruger will send you a manual for free if you go to their website. Alternatively, go to a gunsmith and ask for help.
The Oster 3151 can opener is a soild unit and should not be taken apart to clean.
Disassemble and wipe down the affected parts. Regular cleaning is a must if you want to keep this from happening again