I have to wonder (along with wardancer), why aren't you asking your instructor, since he seems very capable of performing (and using) the kick?
As for how I do it, you can either step across like wardancer suggested, or you can pivot your lead foot all the way around, pointing the heel to the front (you would also have to twist your hips and your lead shoulder), whip your head around, plant your pivot foot (flat, not on the ball or heel, and keep the knee slightly bent) and then do the kick.
The cross step makes the kick easier, but a lot slower. The lead leg pivot lets you do the kick as part of a counter attack, or combination (or right after a shuffle step backwards or off angling). But IMO, a spinning backfist (ala Shonie Carter) would be a higher percentage attack if you really like spinning
I love trying the spinning hook kick in a sparring environment, but I have a feeling that once we start putting the takedowns and groundfighting back into the mix I'd be much more cautious about trying it.