Contact the company for a manual.
Take it to a gunsmith and ask for help.
What Model 51 pistol or a rifle and what model?
Yes.
Follow the instructions in the owner's manual
Send me photos of the rifle and of the markings, and I should be able to narrow it down for you. The email address is in my bio page.
Send me your email address & I can send you a scan of the break down & original manual.
Best to ask a gunsmith for help.
You need to tell us WHICH rifle for us to give you an answer that has any real meaning. Sorry- good questions= good answers.
The link below will take you to the Auto 22 owners manual. Several photos are in the manual
Go to Remington.com and request a manaual.
GREAT rifle and easy to break down for cleaning, Best thing to do is unload it first then look at the owners manual as it gives a complete part break down
Go to Browning.com and click on Customer Service. You can download or request an owner's manual.