How do you install truck tool box? Typical Toolbox Installation Steps First, determine where you’re going to place the tool box in your truck bed. Most people choose to install truck boxes directly behind the cab. Measuring Asked about the measuring tape because were about to measure your truck to make sure the toolbox fits correctly. Inspect the area you plan on installing the toolbox. It all fits correctly or wipe down the surface and get your toolbox ready. Lay Down The Foam This step is straightforward. You picked up from the store and lay it down in the area you will be installing your toolbox in. Make sure the foam has been cut to proper measurements for installing.