Yes, I've not done it, but only with the barrel removed, but the pin can be removed, takes a lot of hammering with a brass drift, or an arbor press if you have access to on, be sure to index it so it can be installed in the same orientation or the barrel won't likely fit afterwards, one member removed it from a brand new rifle for cleaning, the barrel was loose when he put it back together, he sent it back to Gardner to have it refitted.
I'd do the work on a concrete floor so all the hammer force won't be absorbed by the work surface, I use a piece of oak under the frame with the stock removed, and a brass drift with a concave tip to help center it on the round pin head, push it right to left, the left side is splined. A little penetrant may help removal.
Tim