Instructions
Download the "Mega Man Zero 3" hack (see Resources).
Extract the files in the hack to a new folder. Place it somewhere easy to identify.
Open Virtual Boy Advance. Go to "File" and "Open," and select the folder where you extracted the files for the hack.
Click "Cheats" and select "Load cheats." Open the directory where you placed the hack file titled "megaman zero 3.clt."
Load the file. You will know that it has been enabled because Zero will have a white aura around him. His health will be doubled from the original, and the saber will be purple.
Shoot your secondary weapon, which is the x-buster, twice rapidly and press "Down" and "B" at the same time to perform the ex-skill trowblade.