Looks like it may be a Kanger T3S or similar. If the base unscrews from the tank to fill, then the head and coil are screwed into to base. (Although if its the original T3, the head, coil and base are all one part - but you can get new bases to update.)
If that's the case, you can remove the chimney - wiggle it back and forth to pop it loose - to gain access to the coil. There will be a couple of tiny "flavor wicks" on top of the coil and wick. I generally find they're not reuseable, and replace with cotton yarn or cotton teased out of a cotton ball. Once they're out, and you can see the coil, rinse well and let dry. (Blot, don't wipe, excess water.) You can dry burn the coil and wick to get it back to nearly new. Replace the flavor wick and chimney, and you're good.
As said, the flavor can make a big difference in service life of a coil. Some gunk up in a tank or two, some can go a very long time. But with a good clean and dry burn, they can all last a very long time.