Advice on Powering a 1 ohm Sub

I am thinking of purchasing a JBL W12GTI MKII after reading some reviews on this forum it sounds like a great sub to have w/ my system!! I have recently purchased the new Infinity Kappa One 800 Watt RMS amp (2ohms) that I would like to use to power this thing. My question is simple, the sub is required in the spec sheet to be powered at 1 ohm or 12 ohms. I am at a loss as to how I would power just one sub at 1 ohm.. I have researched on several websites with out any success as to how this is done... Could someone please help me out and explain it to me like I'm 4??

Also, I hate to say this but I have a brand new P1224 in the box that I don't know if I wanna open up and try out after reading some of the reviews on this website.... I have 2 enclosures that I can use, one sealed 1.75 and one ported 1.75... I have yet to decide if I am just going to cut my losses and sell that p1224 and purchase the W12GTI MKII / OR just hook up the P1224 and see what happens...

HELP!!!

and please go easy on me.. I'm still learning!