Do you mean in the future on your filter?
If so - then just a rinse out in used tank water every so often is all thats needed,filter media/cartridge shouldn't need replacing at all unless its falling apart.
The carbon wont really hold many bacteria, they will all be in the biomedia portion of the filter. You can replace the carbon, yes, however carbon filters arent really necessary unless you are removing meds or you are just wanting ultra ultra clear water.
Sorry, It's a Marina i25 internal filter & it's only been running for about 3 months. The cartridge has to slip into a designated slot in the filter case so there's no room for putting any old media in with it. My tank is cycled, but it was just a case of when this cartridge is worn out (bound to come a day) surely I don't simply take the dirty one out, throw it away then put a brand spanking new one in with just a squeeze from the old one?? It'd have to cycle all over again wouldn't it? That's the bit that worries me.
Unless the cartridges have carbon in, you shouldn't need to bother about it; just rinse in old tank water rather than replacing them, whatever the manufacturers say
If they do have carbon in, then probably swapping for sponges would be a better option (as long as you don't change them all at once, obviously!)