another question about steel to wood floor

[RShaips]

Ok, I will have all the cross sills, the front panel and the back piece very soon for the wood to fit in. Will the metal floor unbolt and come out ? I am going to take the bed off soon and finish it. Is there holes where the cross sills go ,or do I need to drill them ? Is there a pattern that I can get ? I have the wood pattern details from GMC Pauls site but did not see anything about the cross sills. Thanks