This is how I get mine open when cold.
lay it down on the ground, on it's side between your feet.
With the side that has the seam on it facing up.
With the top away from you and the snout to the left.
put a little pressure on it between your feet, take a 1/2 inch wood chisel and put between the rim of the top and the ridge around the barrel and give a twist.
It opens easy after it warms up.
I'll get a picture of this tomorrow. ;)doak