On my 22/45, the only way I can get the strut into the mainspring cup is to hold the gun level, as if aiming. Then the strut just hangs down toward the cup. The last 1/4" of the mainspring housing lever should then seem "springy".
CZ Gunner, yes the designer was probably on drugs. I only take mine down once in a while when it needs a detail cleaning.
For normal bore cleaning, I use an Otis kit that pulls from the breech out toward the muzzle. So I don't have to field strip the gun.
I've heard that .22LR's don't need to be cleaned. I sort of believe that, but I still clean it. Old habits.
Regards.