Is the lock in the unlock position? If not, work to get it unlocked. Penetrating oil and time. On the left side (can’t see in photo) there’s a bolt that needs to be removed. You will also see a split perpendicular to that bolt that may need the help of a wedge to spread it just enough to let it slide down the tube. Hope this helps.
With the "bolt" protruding outward, and the switch looking to be up in the "on" position, I think he is in the unlocked position already.