The step casting is threaded onto the post. You can drill out the rivets, un-screw the step one turn and re-rivet onto the crossbar. You do not need to dis-assemble the frame to do the job. Take a look at this step casting replacement thread for more information...

http://www.hobiecat.com/community/viewtopic.php?t=2990

An article in the Hobie Class News:

http://www.hobiecat.com/hobieclass/eHCA_News01_02-05.pdf

Also think about the new "chip keeper" modification to hold the chip in...

http://www.hobiecat.com/community/viewtopic.php?t=3150