If you already have the 3 things you need to fill a CO2 Tank then lets get started.  Filling your own tank is quick and easy. I do recommend wearing a pair of thin gloves because the CO2 tank can get a little cold.
1) Hook up your fill station to your bulk CO2 Siphon tank.

2) Hook up your Paintball CO2 tank (20oz or whatever) to your fill station and place the tank on your digital scale.

3) If your CO2 has some Liquid CO2 left in it drain it completely, this will chill the tank and aid in getting a full CO2 Fill.  Hit the TARE feature on your scale to set the scale to ZERO.  Now skip to step 5.

4) Set your Scale to ZERO by using its TARE feature.  If your CO2 tank was empty pump a few ounces into the tank (watch the scale), then bleed it.  This will cause your paintball co2 tank to chill.  You can not fill a warm CO2 tank fully, this is why you need to chill it by bleeding some CO2 out.  A trick to save CO2 is to stick an empty tank in the freezer for a few hours.  This will chill the tank so you don’t have to waist CO2 to Chill the tank.

5) Once your tank is chilled you can fill the tank completely.  If you have a 20 ounce CO2 tank you can put 20 ounces of CO2 in. If you have a 9 ounce tank then you put 9 ounces of CO2 in.  Ect.  NO NOT OVER FILL YOUR TANK.  IF you over fill your tank, the pressure will build to high in the tank and you will rupture the Burst Disk (safety device which stops you from over filling).  Once the burst disk ruptures all the CO2 in the tank will bleed out.  You will have to replace the burst disk at your local store.

6) Shut off the Bulk CO2 source, disengage the pin valve on the CO2 tank, and bleed the fill line, and your done.

Its pretty easy.  Once you fill a few tanks you should be able to fill a CO2 tank in about 1 minute.

Trouble Shooting:

1) You can not fill the tank completely(only a few ounces go in)!  Answers:  a) You didn’t chill your tank enough.  b) Your bulk CO2 tank is empty/Low c) Your bulk  CO2 tank is not a siphon tank (no dip tube).