If you are looking to remove the coil for replacement than you can do as shown in the picture. Use a small sharp object and puncture through the Cotton in any of the juice holes. Then use the screwdriver as a lever to unscrew the coil.
Notes: this will damage the coil so it can not be reused. And don't do this to install a new coil. Make sure your fingers are not atop the juice hole on the opposite side so as to avoid stabbing yourself. Do not do this while the tank is installed on a mod.
When installing a new coil make sure its fully screwed down (by hand is best, you can use a grip pad to help you grip the coil. Don't use a wrench or pliers) Then BEFORE assembling the rest of the tank, test it on your mod (or tab) to see that it's seen by the mod. The picture below shows my mod reading the (.2 ohm coil) at .26 ohm. If it is unread, try tightening the coil a little more. Once you get a proper reading you are good to prime, reassemble, fill and enjoy your vape.
Sent from somewhere in Vietnam.