Its simple really...you go to the Pin Trading area at DownTown Disney & they have I think 10 different 'bases' for you to choose from. Ranging from one hole to three holes. In the hole you are able to put your fave character, park icon or other 'add on'. The 'add ons' are put on with a machine & are not supposed to come off. The 'bases' are $8.50 each & the 'add ons' are $2 each.