When I bought the lights for my Celebration panel, the vendor said to make 1/4" eyelets to put the lights in. I don't have any kind of a punch to open up the holes, so I made some practice eyelets and will use those to figure out the best way to cut. He also suggested using a little bit of Fray Check around the eyelets.

I did the same thing with my Solar System hanging, had enough fabric to slide the battery pack in. Used brass grommets for the holes.

Tree lights
 

I also have this panel to make, one of the dealers suggested to make a small loop of elastic on the back near each hole for the lights. You thread the light through the elastic then into the hole and that will support some of the wires in the back instead of all the light wires just hanging.

I haven't been able to find the lights...made mine after this past Christmas....Does anyone know where I can get the battery lights?? Appreciate anyone's help...thanks

Wait a couple of months. You'll be able to find them everywhere after Halloween. Lol.