you should try taking out the screws with a plus sign screwdriver and opening the shell then putting the insides back in the gun. To look for pictures of the insides of a Nerf gun go to Google and type in your Nerf gun's internal pictures. the shell is the 2 sides of your gun.
taking the gun apart can be risky sometimes.
You will have to find someone who specializes in air gun repair.
A used or broken gun that the company or maker has replaced any of the worn or broken parts. It should be cheaper but just as good as a normal airsoft gun
Take it to a qualified repair shop
Because you, my friend, have a broken airsoft gun.
One that does not fire a projectile (AKA broken)
buy a new screen.........................
If it's still under warranty I would send it back to Crosman or at least contact customer service at Crosman. WWW.Crosman.com
You have to buy a new battery. There is a few ways to repair one. It depends on what you did to it. I recommend a standard 8.4 volt battery. It has a decent fire rate and is affordable
Ahh figure out what the problem part is than figure out how to take the gun apart and put it back together from YouTube, an airsoft forum, or from an airsoft website. Than buy the replacement part and put it in the gun. If the gun was bought for under $100 than you would be better off buying a new gun instead.
Well if the spring is broken, take it to your local airsoft store and ask them to replace it for you. If you have experience with fixing airsoft guns you can just buy a compatible spring and install it you else, but it looks like you don't since your asking. If it is a cheaper airsoft gun unlike a 100 dollars or above weapon purchased form an airsoft retailer, dont bother fixing it. If its not do what I said above.
An Airsoft gun
I suggest that you start by finding old, used, or broken airsoft guns (or your own), and taking them apart, to find out how they work. Then, you would have to find a material to build it out of, such as wood or lego's. After that, all you have to do is put everything together, and hey presto, airsoft gun.