No problem man! Here's a really simple scene I've attached. In the Corona multi-pass settings you add a Texmap, then make sure to enable it. Then in the map slot, choose a Corona AO map. Then when you render, you can change the Beauty pass to Texmap. Then you'll just have to composite it in photoshop using a multiply blending mode.
Another option would be to apply the AO map into the diffuse channel of the material you want AO applied to. Someone correct me if I'm wrong to apply it to the diffuse channel?
Anyway, hope this helps!