It depends on the Make and Model of the rifle.
If it's a Crosman you can find drawings on their web page (see the link below)However I suggeat that you locate a airgun repair station on the web. Look under Air Gun or Airgun repair to find someone close to you. If you are handy with airguns you might be able to replace the o-rings or seals on the airgun yourself but I suggest that you give it to a repair shop and pay them to do it.
You need to take it to a trained professional
This rifle was made by Daisy air gun. (see the link below)
An Air Rifle is either a BB rifle or a pellet rifle. It uses air or gas to propel the projectile.
No
A sporter air rifle and what?
Are you asking how do you swap and air tank on an air rifle, or swap for and air rifle? In most air rifles you put it on safe and swap out the tank by unscrewing it and replacing it.
can i ship air rifle to trinidad and what i need
When you say Air Rifle you are referring to a pellet rifle not a firearm. At present there are no 300 Cal air rifle being made.
Only if the scope is designed for an air rifle. Because of the recoil being different on an air rifle than a firearms rifle. Air rifle scopes are made differently than firearms scopes. A firearms scope can break it's glass mounts if it is used on an air rifle.
First of all keep in mind that this rifle is worth between $40 - $60 used. So don't over spend money on it for repairs if it cost more than it's worth. You can search the web for "Air Gun Repair" and find a shop near you to have it repaired or see the link below.
An air rifle fires a projectile (usually a BB) using compressed air instead of an explosive charge.
Do you mean an air Rifle? NO, Not in the United States.