The toolbox is a wrench storage solution. Using the toolbox, any compatible wrenches can be stored in one item and used.
To remove a wrench from the toolbox, you can craft the toolbox (shapelessly) in a crafting grid while the wrench is equipped. This
will return the toolbox and wrench back to the player who crafted the wrench and toolbox.
Shift right clicking in the air with a toolbox will switch between wrenches in the toolbox. However, if there is a compatible wrench in the player's inventory, it will be added to the toolbox's wrench list.
If you wish to remove a wrench (for charging, in example) you can craft the toolbox by itself in a crafting grid. This will allow you to remove the currently equipped item. (All other wrenches and the toolbox will be kept intact).