I have a 2005 Honda Shadow 1100 what has to be done to change the exhaust system. Would like alittle more rumble sound not like the lawn mower sound it has now.

Your Honda is designed to give you many , happy, trouble free miles. Honda's are known for there stock quiet. Your Honda will NEVER sound like a Harley. When you modify it , it will only sound like a lawn mower with a blown out muffler. If you still want to proceed , you can drill out the baffles if you have a drill bit that is a foot long. If you decide to modify your stock system you have to drill through several chambers of the baffles to relieve the back pressure. With this method if you are disappointed with the out come you can not put the stock muffler back on. Drill only one hole at a time and drive the bike for a day to see if you have achieved the desired affect. If you relieve too much back pressure and develop a flat spot in your acceleration you will have to put in new main jets or a jet kit with needles to restore your performance. You will also have to install a jet kit if you change the exhaust system. I do not have a recommendation for a system . If you go this route be sure the system you pick has a baffle that is adjustable or changeable so you can adjust the sound. Warning: all aftermarket systems will be louder than you want them to be and ear plugs may not be enough to help.