ACDLCinst is a small web application that installs all official DLC items and some custom ones into Animal Crossing City Folk savegame files. Nowadays, the DLC items have become unobtainable due to the shutdown of Nintendo's online services for the DS and Wii systems. Using this tool, however, you can install three previously unreleased DLC items as well: blue Pikmin, yellow Pikmin and red headgear.
First of all, please check if your town features HDLC items. These are unofficial, custom items that were distributed by hackers around 2009. If you don't have any of these items, you can skip this paragraph. These items are not supported by this tool due to being outdated and mostly unfinished. Try to remove and sell every instance of them, including dropped items, inside player homes and the auction house. The tool will attempt to remove most occurences, including shops and inventories.
To use this tool, you have to dump your savegame file (rvforest.dat) from the system. There are several Homebrew applications that can manage savegame files, one of them is SaveGame Manager GX. Simply select your savefile using the button below and you are ready to go. Please make sure to keep a backup in case something goes wrong. The tool will add the DLC items to every available player catalog.