The sights on an air rifle are held to the rifle's frame by either taper pins or small screws. If your air rifle uses a taper pin to secure the front and rear sight, you will need a gunsmithing tool kit to remove the taper pin. If your air rifle uses a small screw to secure the front and rear sight, you will need a small flathead screwdriver to remove the screw. You can visit the corporate website of the maker of your air rifle to order a specific sight replacement.
Open the air rifle's breach and remove any BB or pellet in the barrel. Leave the breach open while you are working.
Locate the sight or sights on the frame of the air rifle. Check to see if the sight or sights are held to the frame with a taper pin or a screw.
Remove the taper pin or screw that secures the sight or sights to the frame using the gunsmithing tool kit or the screwdriver.
Pull the sight or sights off the frame of the air rifle.
Insert the new sight or sights onto the frame of the air rifle and secure the new sight or sights in place using the screws or taper pin supplied in their package.