Terry,

You have to remove the magazine tube to get the forearm off. If the screw that holds the front mag plug in goes into the barrel it has to be removed but if it only goes in part way it can be left in. remove the two screws that hold the magazine cap on. there will be a pin between the barrel and the mag tube in the mag retaining ring, tap that out. Slide the forearm cap forward so its loose then put some oil on the tube between the retaining ring and the forearm cap to help it slide through the retaining ring. Now it should slide out unless its has glued itself in with old grease or rust.

Bob