Yes you can.
@F-machine has provided you with an excellent tutorial above.
The choice of your first flavoring (Mint) might be a slight problem. Stronger flavors such as Cinnamon, Menthol, or Mint tend to "carry over" or "bleed over" to the next flavors that you use next. I would never try to refill a carto that had tobacco or coffee flavors in it previously as they are pretty strong, too. What works best is fruit or desert flavors, which you have chosen to try next.
Back in the day, some folks would boil and dry their old cartos in an attempt to extend the life of their cartos. I never found that very satisfying. It was always best to start out with a new fresh carto.
I would always add liquid to the point that the polyfill wick material glistened like a wet slushy drink. Not adding enough e-liquid can cause the coil to burn the polyfill, and you'll NEVER be able to remove that burnt taste no matter what you do. I describe how to add e-liquid to a carto in the below blog. You can ignore the second part on the cartotank part.
Baditude's Cartotank Setup Guide