how do i put an mdl0 over a character?

[arcray20]

to be more specific, to put the Yuroichi model over Metaknight like Nel
from here:

http://forums.kc-mm.com/Gallery/BrawlView.php?Moderated=1&Reported=All&Wifi=0&Name=*yuroichi*&ByUser=*&Credit=*&Info=*&Thumb1=*&Type=**&TypeAlt=*

i tried looking for some kinda of guide, but i think im looking in the wrong places