You have to hit it with a slede hammer until it breaks down then you've done it
What Model 51 pistol or a rifle and what model?
Go to Remington.com and request a manaual.
Yes, they are directly available from Remington Arms. If you contact them via their web-site Remington will send you one. The RH or LH basically requires the same type of maintenance.
Go to Remington's website and and you can download one or have one mailed to you.
Go to Remington's web site and you can request a manual for free.
Go to site listed below you can download the manual for free. http://www.remington.com/library/downloads/owners_manuals.asp
$350 Down south
Send me your email & I'll send you a copy of the original manual.
Ask a gunsmith for assistance.
You need a gunsmith
Ask for help at a gunshop
Take it to a gunsmith