This is for Lance.....he's been asking for "tips".
Not sure if this is in the Anderson video but I have been getting several very old pools that don't have valving or access that would make my task easier. So I welded a long tee handle on a 1/4" pipe tap and purchased 100- 1/4" plugs to seal the hole after I'm finished drilling taping and testing. I have not located solid pvc plugs that could be glued in and sawed off flush when finished. So far the only plugs I have found look like nylon and are hollow. If you try this yourself be sure to drill at a fitting or coulping so you have plenty of thread depth. It only takes about 90 seconds to drill and tap PVC.