Ask a gunsmith for help. Check out old gun books in the library.
To take down your AMT 22 caliber Backup, first ensure the firearm is unloaded by checking the chamber and magazine. Next, push the slide back slightly, then locate and press the slide stop lever to release the slide. Once the slide is removed, you can take out the recoil spring and barrel for further disassembly. Always refer to the owner's manual for specific instructions and safety precautions.
$175-200, depending on condition. Went out of production in 1987.
Best left to a gunsmith
AMT went out of businees and was bought by another company that kept the name. They only make pistols.
25-125 USD or so
50-125 or so
$300, plus or minus $50, depending on condition.
Best to ask a gunsmith for help
How to take apart Coast to Coast Marlin 22 cal long rifle Model 00550
75-200 USD depending on condition.
Honestly, depending on condition, 350.00 to 450.00
Best to ask a gunsmith for help if you don't have a manual