Hello Dave,

Simply unscrew the magazine tube (using the lever on the end of the tube), taking care not to rub the bottom of the barrel with the lever locking mechanism.  Once you have the mag tube fully turned out of the receiver frame, pull it completely out and set it aside.  Then, fully open the action so that the extractor clears the slot in the barrel. At that point, grasp the barrel assembly and turn it 1/4 turn and pull it forward (out of the receiver frame).

Sometimes the barrel assembly might be stuck in its normal position due to dried oil & grease.  Using a few drops of Kroil on joint between the receiver frame and the take down extension ring will usually free it up.

This video might help – Winchester Model 55 Up Close Plus The Rifle Man 05-01-2018 – Bing video

Bert