How to free space on ISO?

[Metanightmare]

My SSBB ISO ran out of space after I added some custom music. Now WiiScrubber says: "Unable to find free space". I've read somewhere that you can free space by deleting masterpieces or replacing dummy files with 1 kb versions. However, I have no idea where the dummy files and masterpieces are located in (in the ISO) and I don't know how to replace the dummy files with smaller ones.

I'd be grateful if somebody gave me a direct path to masterpieces or told me where the dummy files are and how to replace them

 

[Doomolish]

I have a related question:

I know there are Brawl isos that are just 4gb long, but mine it's 8gb. I tried to download 4gb versions but just didn't worked. Is there a way to shorten it to 4gb, or you can help me to get a shorter version of the iso?

Thanks in advance.

 

[IkaMusumeYiyaRoxie]

I have the same problem too. I was updated the "smashbros_sound.brsar" file and replaced some new voices clips for any fighter, and I can't replace the brsar file.