I assume you are talking about gingerbread? If you are on gb rooted, you can download the deodexed version from the tbh app or mirrors on p3's post on mydroidworld. It can be flashed over gb rooted without wiping. First boot will take a while, be patient.
I guess you could look for .odex files to make sure they're gone but I don't even know where they would be lol. I just trust tbh that when I flash something they release and no errors pop up then it worked