As far as I know, to change the boot LOGO you first create the proper image file and package it to a sbf, then using rsdlite you flash it. It only changes the boot LOGO and nothing else.
I've never done it personally, however I knew a guy on Droid forums who would take what ever image you wanted and turned it into the sbf file, all I had to do was flash it with rsdlite. I use to do this regularly on my OG Droid, however I've not tried it on my Droid X2. But I don't see why it should be any different.
That being said I'm pretty sure there is a tutorial on the whole process over at Droid forums.
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