Hey, sure thing. These days all you really need is pk3DS and a copy of the game in cxi or 3DS format (you might need both versions if you want to share the hack). Then you use pk3DS to unpack the game into separate files (click tools -> extract), and open the folder containing those files with pk3DS. From there you can edit whatever you want, and when you're done, you copy the files you edited into a folder in the same way I've done it for my USUM hacks. If you need more information I'm happy to help!