Need help removing bolts in van

Spaulding near Hutchinson, Chicago IL

Description

I have a 1989 Ford E150 that I'm converting to a small home. The van was previously factory built out which we are completely removing, there are bolts in the floor of the van that I need removed. 4 of them hold down the bracket for one of the captains chairs that were removed, another is holding a bracket. I do not know if these bolts need to be there or not and i do not want something (like gas tank) hitting the ground. If the cant be removed fine but if they can I want them gone. It's going to take more than one person unless you just cut them off with a grinder.