Mbm Editing

I've tried customizing my Symbian Splashscreen and Shutdown animation(SysAp.mbm) to show my own pictures. But if I rename my pix extension to .mbm and apply the patch it doznt seem to work. I even tried to change the extension to .mbm using xenview but it makes the picture totally unusable for my Phone(N95 8GB)....
My point is, I want to make mbm pictures.
Please any good application to help me with this?
And where to download it from.
I'll appreciate any help pals...
Tanx alot in advance :)