Step 1: Unscrew the booster cone (clockwise)

Step 2:  Press the cover latch, and lift open the receiver cover.

Step 3:  Crank the handle forward.

Step 4:  Now lift up on the top of the lock while allowing the cocking handle to slowly ride forward, this will free the lock from the rails.  You may now twist the lock 1/4 turn counter (anti) clockwise, disengageing it from the interrupted threads.

Step 5: Press the fusee spring cover latch, and carefully (spring is rather strong) push the fusee cover towards the muzzle of the gun.

Step 6: Now move the cover away from the receiver of the gun and release the spring tension.  You can lay the on the gun and disconnect the spring linkage.

Step 7:  Lift the feedblock out of the receiver.  Be careful to watch the lower feed pawl (circled in figure below), once the lowe feedpawl disengages the barrel extension - make sure you move it out of the way of the topcover, so its tucked under the feedblock.

Step 8: Still lifting (mine is pretty tight).

Feedblock removed:
 

Step 9:  Lift the stock/cover latch, and flip down the buttstock.

Step 10:  Grasp the cocking handle, and remove the barrel extension and barrel.

Step 11:  Done.

and - because I am lazy, and don't want to go through it all again... reassembly is the reverse of disassembly!