How do you remove Shimano Hollow Tech Cranks
 

I just bought a used Cannondale 1-FG single spped rigid disc... wicked fun, doing maintanance and WOW never seen Hollow Tech Cranks before... I have a crank puller, but with the hollow spindle it doesn't work... how do you get them off?

You need to use a thingy that threads into the bottom bracket's (larger-than-square-taper) hole, and a typical crank puller presses against this in order to force the crank off. Not sure where you can get them though.

Park Tool also has instructions for removing and installing cranks with Octalink or ISIS splined BB's.

I understand a nickel will act as a plug to give a conventional crank puller a firm surface to work against. Shimano supplies a small steel plug tool with their cranks for this use but you can improvise.

Sure you don't have self-extracting bolts on these? Did the "dust cap" have a hole in the middle?

The instructions you want are actually here.

a nickel will not work. I reccommend going to your LBS and asking to buy one, or borrow one if they wont sell it to you. I borrowed one from Mesa Cycles in STL (Thanks Mesa.. you guys are awesome) a while back. The peice is a solid steel "tophat" looking peice.

I actually tried a 2 eurocent coin originally, but the coin bent and it honestly caused me to almost hae to drill it out. Get the tool...dont break your cranks trying some other wackjob method.

For every HTII crank I've ever removed, you just take off the non-drive side crank arm then pull the crank out by hand from the drive side, although you might have to help it get started with a rubber mallet. Am I missing something?

HTII cranks are the new external bottom bracket design and your removal instructions are correct. We are describing removal of the previous Octalink cranks which I believe were also called "Hollow Tech".

The "plug" supplied with new Shimano 105 cranks is Shimano tool TL-FC15 and, as ranger5oh noted, looks like a small steel top hat. Bike shops should have a lot of them as extras since they do come with every 105 (and maybe below) crank set. Ultegra and Dura Ace replacement sets don't include it because they have an auto-extract crank bolt design and don't need an accessory tool.

The OP might want to take pity and tell us which HollowTech he has - the 9-speed HTI or 10-speed HT-II.