Go to www.aempower.com and select cold air replacement and your make and model. You will then see a screen for replacement filters AND the recharge/filter cleaning system. It is around $10.

Edit: You can purchase it through some online dealers or pick one up at an Autozone or Advance Auto Parts. BTW the AEM filter is really a K&N cone filter so if you see a K&N cleaner/recharge kit you'll be in business.