Look straight down into the action from above.
There will be a small 'tab'(lever release) extending from the area below the breech face into the opening taken up by where the barrel lug had been.
Press down on that tab (with the end of a suitable tool like a punch or tip of a screw driver) to release the top lever.
It helps to hold the lever open as far as it will go to take the tension off the lever release while pressing down on it.
Makes it easier to push down,,then allow the lever to go to the closed position.
