So as I read my Headlight Resto Kit Article I realize that it can be confusing to read. So here is a easier How-To DIY to follow
Grab your truck keys and move to a desired location.
1994 Ford Ranger Used as Example
Place a Tarp in the back of your truck.
Push the tarp into the the corners of the bed for easier filling and less spills
Fill it with water!!!
OK I lied... Their is a 4th step
And its even Mobile so you can take your pool to a friends house. (might have to add water after driving there Driving untested)