OR ya could do it the redneck way:
Using an old compressor for vacuum pump, you need gauges so that you can connect the vacuum pump to the high side, the freon to the center hose (yellow) and the blue hose to the ice box.
On the first photo that can of freon has an old school can tap from back in the day. That tap will hold that gas in the can forever. The newer screw on type tap from automotive stores ain't worth nothing. Once you tap into the can the thing is gonna leak out in a day or 2 . This tap made by Richie (I believe) is a nice one. Even though the plastic handle broke years ago it is still better than any newer style tap.
I soldiered son bicycle valves on the old compressor and made a vacuum pump out of it. It also does a great job airing up tires on my lawn mower and vehicles.
Like I said you need gauges though if you intend to repair a leak. Any air in the system and you will have ice. Ice means blockage and restricted freon flow means no cooling.