You will need a 3/4 inch 3/8 carriage bolt (one with a square head underneath the head of the bolt) and a lock washer to mount the Dyna to the muffler bracket on the bike. Insert the carriage bolt in the Dyna rail then move it until you get it in the hole on the bike then put the nut and lockwasher on. I didn't do the 10 degree bend, I just put it on stock. The exhaust hits your rear brake cable assembly but the purists don't like to see soot on their chrome. I've blacked mine out so it doesn't matter to me.  

Yes, a little bit. Actually you should remove the header pipe from the motor, install the Dyna and then reinstall the entire assembly in one piece. If you pound on the Dyna or push/pull too much you could break off the header bolts or crack your cylinder.  When you put everything back on basically loosely bolt up everything so you still have some play, get the bolts on the mounting bracket at the Dyna all lined up so you know they fit, then start tightening up the header.  Use a 1/4 inch ratchet, FINGER tight!! Then the muffler bolt, then tighten down the header, again two fingers on the ratchet, you can break the bolts off in a heartbeat. Be sure you put anti-seize on the header bolts. Then tighten down the Dyna bolt.

By the way, did you do the tin can gasket? It'll leak if you don't....

You can probably use a regular bolt but it's a tight place for a wrench. The square head on the carriage bolt slides into the rail and holds the bolt in place while you crank on the nut, so it is a one wrench deal, not two.

so what you gunna do with the other one?
sell it to me?