If you have the CO2 in the cylinder, it's most likely that you know how to remove it since you probably loaded it. But, maybe not. Maybe your buddy hands you a Byrna to try out and you need to remove the CO2 cartridge.
The Byrna SD & HD use an 8-gram CO2 cartridge for the Byrna cylinder, and the Byrna SD (HD) XL uses a 12-gram CO2 cartridge for the expanded cylinder. (Same goes for a Byrna SD with the Byrna Boost installed.)
The removal instructions of the 8g CO2 cylinder and 12g CO2 cylinder are the same.
When there is insufficient CO2 gas remaining in the cylinder to fire a projectile, your Byrna launcher will remain under pressure. Always keep the barrel pointed in a safe direction when unscrewing the CO2 cap to avoid any accidental injury.
REMOVING THE CO2 CARTRIDGE
1. Put the launcher in SAFE mode. Remove the magazine. And make sure there is not a projectile in the breech!
2. Point the barrel in a safe direction (not at your face) and release any remaining CO2 gas by unscrewing the CO2 cap with the CO2 cap tool (built into the magazine base - because Byrna engineers are so smart!).
3. Remove the CO2 cap and used CO2 cylinder.
4. Replace the CO2 cap.