Step 1: Lie on the back with the legs extended. Keep the same hand position the entire movement. Keep the legs rigid the entire movement.
Step 2: Alternate the feet between 24 inches and 6 inches.
Tips: It is very easy to want to raise the up leg to a 45 degree angle, but all this is doing is reducing the amount of work the abs are doing. Don't cheapen yourself!
Link™ to Exterior: Handles or middle of Link™ held in extended hands
Stance: Lying on back. Legs fully extended