Use Hoppes
To break the powder gas fouling. Then remove the roll pin in the sight base and try to twist the tube to break the bond. Use the Brownells tool but nver a plier as it can crimp the tube. Some bases are overdrilled and a brass drift on the opposite end can be used to force it into the front sight a little, breaking the bond.
Gas tubes leak some but eventually, this is sealed.
On the removal of a front sight, the pins are driven out from right to left. The right side of the rifle is the side with the ejection port, rear sight windage adjustment etc...
You need a solid rest, solid punch cupped to fit the pin and a good hammer. For the rest, I recommend a hard lead block, about 10 lbs grooved to fit the barrel. Place this on a very heavy bench anvil for added mass. You need a SOLID rest. If this isn't available, use the lead block on a concrete slab.
Mask the surrounding area with heavy layers of electrician's tape to prevent damage to the finish. You only need to see the pins. Do not mask the side that contacts the rest as the lead will protect.
Reinstall with blue threadlocking compound on the pins.
Clean up lead smearing with Hoppes #9 and a toothbrush.
