VB3 decompiling

Hi im recently donwloaded dodi full installation, my problem its with the app decompiled... the app that im trying to decompile have custom controlls and give me vbx files(on folder setup)..(3 of them only).. on the manual of dodi's says:
Custom Controls (VBX)
VBDis needs descriptions of all custom controls used in a program, in order to show the properties and events. These descriptions are provided in data files with the extension '300' (for VB 3.0). If a program makes use of additional VBXs you must edit the sources, before you can start the program in the development environment.

My question HOW I CAN EDIT THE SOURCES??? THIS ITS BEFORE OR AFTER I MAKE THE DECOMPILATION??? WHEN I MAKE THE DECOMPILATION, the DODI APP SENDS ME MESSAGES SAYING ME THAT "MISSING DESCRIPTION FOR C:/VDESC/ X.VBX"(this vbx file its included on Setup folder of the app)..... THATS THE REAZON I GUESS THE EDIT PROCCES ITS NEED MAKED BEFORE THE DECOMPILATION...
ANY IDEA???
THANKS amigos!