Tool Box (another request)

Hello Forum,

I finally ordered my storage box. It measures 32"Wx 12.5"H x 12"D. It's aluminum and it's black. I want to attach this to the bed of my truck. I aplogize for posting this question again but I need some fresh guidance. I want to attach the box to (2) aluminum brackets which will be attached to the truck bed using 4 bolts. On the inside of the box I will use wingnuts so that I may easily remove the box by simply opening it and then removing 4 wing nuts. Has anyone done this, or something similiar? Is the underside of the bed accessible enough to use bolts & nuts from the bottom for the bracket? If so, please provide info and pics, if possible. This forum has been very helpful with all my questions and I hope to receive the same assistance with this. Thanks!!