Market place modules and art assets

I just purchased Odyssey of the Dragonlords module (5E) from the market place.  Looking through it, I noticed quite a few of the 'monsters' are just round tokens with the name on them.  I own the monster manual so I should have all the art assets and I assume it should transfer over.  Is there a special process to include this or will I have to update all the tokens with the art assets from my library?  Thank you in advance

Odyssey of the Dragonlords is 5e, but it was produced by a company other than Wizards of the Coast. Licensing issues prevent the publisher (Arcanum Worlds)  from using material not in the SRD, and this includes all WotC artwork. Your best bet is to replace the default tokens with tokens of your own. Laborious yes, but one of the realities of publishing a third party product. Commissioning art can be expensive.