[mattsm]

just go into the extended rom with file explorer or total commander and delete everything in it. Nothing that is contained in that partition is needed. Then after you have done that, do a hard reset and let the customizations run from his rom. A hard reset will not write anything back to that extended rom. Once the contents are deleted, It will be just like another partition of storage space that once you write to it, it will always be there no matter how many times you flash a rom, unless you delete the files that you put in it.