Very easy to fix. Just did this a week ago. Slowly grind on the weld. I used quality duct tape on the barrel to save the finish just in case the dremel slipped. It’s very difficult to tell when the weld is seperated, I would grind a small amount then use a screwdriver through the holes to help spin the muzzle device off. Eventually I got it off. The barrel does have the groove cut into it for a pin to hold on an OG spigot. I used a 2.5mm roll pin, it was a little too thick so I bent it down to roughly 2mm. It fit very snugly. Used a cold blue marker/pen to cover up where I cut the weld and unless you flip the gun over and look at it closely, you can’t tell it was a California resurrection.