If you have a tightly-fit tank and you cannot pull it apart, you really should try Coil Master vape tweezer out. Fix the tweezer in your atomizer, squeeze it and turn the tank,then you will find it super easy to loosen and unthread the stuck bottom ends.It is a great helper to get your cap out of your rda as well.Vape smart with the smart vape tweezers! .Apply to atomizers of 22-25mm in diameter