I have been working on a gun and I have had to put it together and take it apart many times. I had read the suggestions on this site and I really did not want to cut a hole in the stock. I worked on an idea for reassembly that seems to work well. I have used it on this gun several times. As you can see from the picture of the stock it was cracked into many pieces and had to be put back together. First you may have to take a file or dremel tool and cut the sharp inside edge off the stock where the cocking rod sits on the right side of the stock. If you look close you will see a natural hole located in the cut out for the cocking rod to turn in. This hole feeds into the openning lever tunnel on the front of the stock. By cutting the sharp inside edge of the stock it will increase the hole size between the stock and the cocking rod slot. It does not require a lot of wood removal. See the picture of the stock.
Second I cut a piece of nail and drilled a small hole in it and put a piece of fishing line through the hole and tied a knot in the line. The nail size (in diameter) is determined by the distance from the lever spring to the side of the cradle the spring is located, with the openning lever locked to the right. Once you have the nail in place release the lever by pressing on the barrel lock and return the lever to the middle position. Now the piece of nail with the fishing line through it has all the spring tension on it.
Assemble the gun with the fishing line coming out the right cocking rod slot. Then push the openning lever to the right and press and pull on the string and the nail piece jumps out.
Buy making the piece of nail rectangular and thin with rounded corners you might not even have to take the sharp edge off the stock.
See the pictures below.
http://i236.photobucket.com/albums/ff189/seaboltj/DSC00805.jpg
http://i236.photobucket.com/albums/ff189/seaboltj/DSC00810.jpg
http://i236.photobucket.com/albums/ff189/seaboltj/DSC00814.jpg
