Trying to rip from 'Sonic & All-Stars Racing Transformed'

Hello. I'm trying to rip the Skies of Arcadia map models from 'Sonic & All-Stars Racing Transformed'. The Delphinus model looks too sexy and I must have it. Where should I start by ripping them? I have a Steam copy of the game and in the data folder I see these files.
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Those 'GameAssets' files look really tempting to me. How could I open these files? I've been searching for hours but to no avail.