Im not to technically handy with guns so I have no idea what I woyld be looking for with out someone next to me or unless someone looked at it for me. I have the newer gen utg shadow ops l96
Being a competent sniper / airsofter is all about knowing your gun. You can easily learn by looking up youtube videos, but I could also guide you as best I can in writing.
-Most L96's come in the box needing to be assembled (basically, screw the upper receiver to the stock). Reverse this, and separate your upper assembly (receiver, outer barrel, trigger, and internals) from your stock (the body of the gun), making sure that the screws are completely un-threaded before you pull. Make sure to gently guide the mag catch (attached to the outer barrel) if needed while separating the upper and lower assemblies.
If you are using a stock (read: all factory original parts) L96, then you can just remove the trigger mechanism without opening the cylinder. Simply pull up on the spring guide stopper (the metal bar in front of the actual trigger) slowly and straight, but don't pull it with the intent of completely removing it from the the box; just pull it out enough to get it free of the spring tension. It (the spring guide stopper) should wiggle or slide up and down more easily once it's cleared of the spring tension.
now you can simply remove the whole trigger mech by unscrewing it from the receiver. Make sure you don't loose any of those tiny screws.
Inspect the piston sear (this is the sear on the top of the trigger mech). If it's stuck down, see if you can pop it back up. Does it return to and stay in the upright position easily? It should rebound to the upright position
Look at the top trigger mech / box. That's what your trigger should look like, minus the spring guide stopper. The piston sear should be popped up by a tiny torsion spring inside the trigger mech (not visible in the picture). You could also check to see if that spring is broken or off alignment by opening the trigger mech (go slowly, because there are tiny springs inside trigger boxes).