Why is myblu Tank™ unit stuck?
If you are unable to unscrew the blu Tank™ from the battery by hand, gently squeeze and turn the blu Tank™ with pliers. Do not use the pliers on the battery! Once you have freed the blu Tank™ from the pliers, discard it immediately.
The most common cause for stuck blu Tanks™ is over-tightening by the user. You should stop screwing the blu Tank™ into the battery as soon as you feel resistance.