You buy a tapper valve.
Refrigerators are typically factory charged then sealed and there are no access ports to do what you are asking.
R12
Refrigerators use magnets on the door the keep the cold air in, Same with the freezer door.
A curator
You don't. This is a job for an expert.
You lift and transport them upright. Laying on their side or back will displace the refrigerant.
should be preformed by proffessionals only
You refill the refrigerant through the low pressure port. See the related link below for a picture, and you can check your owner's manual for a more detailed description.
Just go to any auto parts store and buy a can or two of refrigerant. All you do is take the cap off the hose to the air conditioner, screw the hose from the can into it and refill it. Its easy. If you suspect you are leaking refrigerant, you can buy a refill with flourescent coloring to help you locate the leak.
It is called refrigerant. Take it to a professional to repair the leak as you have one if it is low of refrigerant. He will then fill it up.
there is a connection on canister its the only connection the refill hose will fit
Why do you want to refill it is there a leak? It depends on the type of refrigerant and how much refrigerant will be needed. Check with 3 or 4 heating and cooling service establishments and get an average of what there charging in your area.