I have one of those too. The tank comes apart at the base and the top. When you take the base off you will see the part that is called the coil. That will also screw off simply by twisting it counter clockwise. I take all the parts off and rinse off with hot water from the sink. Then I take them all with the exception of the coil, and place in a bowl of the hottest water my tap will put out. I let them soak for about 10-15 minutes and rinse again, and then I set aside so they can dry.
The coil itself I soak in white vodka for 12 hours, usually the entire day or overnight. After it is done soaking in the Vodka, for the said time period, I place them in a bowl of hot water from the tap for about 15 minutes. This is just to get some of the Vodka out of the coil/wick. Then I place them out to dry for an entire day.
That coil part is the part you can purchase separately, and they will need to be replaced every 2-4 weeks depending on flavor/vapor production decline. I find with proper cleaning these particular coils can last longer than say my Aspire Nautilus coils. You can usually find these coils at your local vapor shop, however, not all shops carry them--so call in advance.
You can also purchase them online for a much better price. I can find 5 packs for about $11.00 online with free shipping. Don't forget, to check the various vendors in your area because I have found them at the local B&M for about the same price. I've also seen local B&M's sell them for $25.
I hope this helps.
Skeebo