It's not as hard as you may think. There is a wedge pin just ahead of the cylinder, held in place by a screw on the left side. Remove the screw, and tap out the wedge pin with a non marring hammer or wooden dowel from right to left. Some models have a spring within the wedge that will need to be depressed while driving out the wedge. Once the wedge is free, the barrel may be wiggled free or the two alignment pins on the frame, located at the front of the frame near the cylinder ram rod. Once free of the pins you can remove the barrel towards the front. Half cock the hammer to dis engage the bolt from the cylinder, then slide the cylinder off to the front. I have provided a link in the related links section that may be able to help.
Best to ask a gunsmith to show you how.
how much is a 1851 colt navy 36 gun
It appears that this is a Colt New Model Pocket Pistol Of Navy Caliber. The engraving on the cylinder should say Stagecoach Holdup.
Proofhouse.com has Colt sn data.
Colt 1851 Navy sn 179639 was made in 1864 (175000-179999)
The 1851 Colt navy with serial # 112343 was produced in 1861. (98000-117999) about 1861
Proofhouse.com has Colt sn tables. You can also call Colt and they will tell you.
Colt data at Proofhouse.com
check colt manufacturing for colt 1851 with full loading and shooting directionss i just reviewed this article and it is very clear a lot of info on 1851 navy colt, good luck.
it was made by Colt in 1942 for the U.S. Navy.
1.000
made by Colt for the US Navy in 1942