I have 2009 Street Gluide; I am looking to upgrade to Rinehard or V&H slip ons. Can someone lay out the facts on what is truly involved. What changes are necessary when just adding the slip ons? Do I need to spend the money for the down load after installing slipons? At what stage is the tune module needed? Can I install the slip ons myself; and then have the dealer do the down load (if necessary)?