Remove the fore end. The action tube has 4 holes through it. Clamp the action in a padded vice and put a punch through the holes and twist the action tube off of the screw that holds is. You **may** need to heat the action tube to break the thread locking agent bond. Pull the action tube out of the action bar assembly and replace the O-ring while you have the rifle apart.
Mr Dave is correct. May is the operative word. I’ve disassembled several and so far I have NOT had to use heat.
I have the Brownell’s tool for disass. I have used a short 2x4 to jar it loose.
It really isn’t complicated. Good luck.
Jerry
