You mean a cartomizer for a KR808D-1?
Yes, you can. If you want to get rid of the prefilled liquid (because you don't like or whatever) just place a tissue around the battery end of the carto and blow
gently to get out the excess fluid.
Then gently pry off the white cap, remove the little clear rubber O shaped ring inside and run water
through the carto.
Once you get to a point where you no longer smell any
eliquid in the carto it should be clean.
Blow out the excess water into some tissue again until its dry. Some people let the carto dry over night- but in my experience if you blow enough of the water out it'll be fine.
Be sure not to over do it- don't use fast running water, or water that's too hot or too cold. The key is to
rinse the carto, not blast it into next week.
Then fill it with up to 20 drops (give or take) and you should be good to go.
oh and here's a helpful video from the V4L subforum about how to refill a cartomizer:
http://www.e-cigarette-forum.com/forum/vapor4life/39350-refilling-cartomizer-movie.html