Replacement fuel tank

After dealing with a hefty dent in my fuel tank that has allowed a dismal max fuel capacity of 12.5 gallons for far too long, it's time to finally fix it. My XJ is a 96, and I've got a tank from another 96 in perfect shape ready to go. What do I need to do to as far as cleaning out the inside of the replacement tank and preparing it for installation? I've heard people say to put some gas in it and shake it around until clean, and I also believe I've heard something in reference to kerosene. Any truth to what I've heard?

Az, I just saw a segment on this from extreme 4x4. They used a product from summit racing to seal the tank after cleaning it. It looked really easy. Came with a cleaner, prep agent and then the sealer. Here is the link for the kit :
http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM-900056-3&N=700+115&autoview=sku
It was just a matter of pouring the stuff in and shaking it around. The sealer would do you good so that way you know there aren't going to be leaks when you put in your new tank. And the best parts is it's cheap. Hope this helps.

I just bought this stuff saw the same episode.. I've got pinholes in my tank on my 95 and rust on the outside.. doing this process this weekend.

I'll pot up pics