If you use the locking pin it will bugger up as the bolt is very tight. 
I made a tool that bolts onto the front of crank then you can use a 22mm socket to undo the crank bolt.
If you have air con, its a bit more fiddly but still straight forward enough to use.
If you send your email to mekkannatrix.nar-ha AT THE HOT PLACE DOT COM I will send you some pictures of it.
Julian alias Fwaddar Motors
                
 Fwaddar Motors
                
 January 2010