The end if the barrel has a flat machined on the top side the angles toward the bore at the muzzle end so that it wedges the sight tight on the barrel. Take a block of wood or other soft material that will not damage the sight. Place against the sight to hit with a hammer to free the sight from the barrel.Mike
If looking at the muzzle end from the side it would look like the top half of the barrel has a slope down the muzzle. the inside of the sight has a corresponding slope so that when the sight is pushed on it wedges tight on the barrel. It just need a light smack forward to come off and then should be able to be twisted off by hand.Mike
When i did mine I used an adjustable wrench (not pliers) adjusted to fit around the front sight sleeve and just twisted it off of the barrel.As for the barrel screws I believe the screws help hold the barrel in place. I installed set screws in mine. What did you get a 22 or a 177?
I should get one in 177. .22 gets expensive.Try this...