I think if you are signed into the forum, and go to your original post it will give you a button at the bottom that says "edit". Once you click that, you should also then have an option that says something like "advanced edit". Click on that and you should be able to see your original post and change most anything you want to.
I'm not sure about editing a PDF file - I think that is pretty hard without special software. The only thing I would try with normal software would be to try and copy the text and paste it into MS Word, then edit if possible and repost as a Word document.
2004 Vulcan Classic 1500 - carbed
Grips, Freeway pegs, engine guard
Floorboards, Nomad rear seat,
Custom made luggage rack, Windshield & Lowers
Saddlebags, Passenger floorboards,