I assume you are contemplating converting your Trek District 8 and there are challenges but nothing that can't be overcome. Most others have discussed what will be needed and the costs associated with the conversion. I wonder if it is financially more fiscal to sell what you have and purchase a Trek Lync 5. It has everything but the dynamo but does have the USB charged lights. With the Lync you also get the carbon belt drive which you may or may not like. Your conversion would be cheaper but having a nice new shiny bike may outweigh that.