that's a good one....
Can you get a hacksaw blade down between the footpeg and the mount?... might help if you pull the whole mount off the bike...
Then, if you can, cut the bolt and remove the peg.... the last nub of threaded bolt should be fairly easy to get out... either by tap and turning with a screwdriver, grabbing with visegrips, or drilling...
if you can't do that... you need to drill up from the bottom,..use a bit slightly smaller than the threads, center punch the bolt first... once you're in about 1/2" you should be able to tap it out, the remaining threads will collapse or break off,..then clean out the remnants with a fresh bolt...
Part no. 09106-06100 bolt $2.91
http://www.ronayers.com/browseparts.cfm?SearchString=09106-06100&adv=5&kw=fic...just remembered,... there's some kind of tin shim thing that goes between the footpeg and the mount... hacksaw may chinker that up...
here's the parts fiche..
http://fiche.ronayers.com/Index.cfm/Module/Main/TypeID/26/Type/Motorcycle/Mak...part no. 43570-24B01 cushion $4.54
your call...