Below will explain in depth and have visuals of how you can make sure you are taking the right precautions.
Having trouble with making sure that your canister is fully empty before sending it back? Here are a couple of things that you can do in order to make sure that you are taking the correct and safest precautions to do so.
First, there is a center pin at the top of your bottle, you will want to make sure that you are facing it away from you or anything you could potentially harm in case there is still a little CO2 in there. Doing this outside would be best.
Second, take a spoon, and decompress the canister from the center of the pin on the top of the bottle. This is to ensure that any CO2 that is left is gone and safe for you to now store or ship back. If nothing comes out, then the canister was empty already.
After decompressing the canister, you will want to take the cap that comes with it and make sure that you are twisting it on to make sure that it is closed and secure for being shipped back out.