Initially, cut two pieces of the gel wit red and blue colors, to cover the lens of the welding glasses. Try to line up the lenses so that it can filter the light which passes through it. Keep the lens back on the frame of the welding glass. Glue the LEDs with outer sides of the frame and point it outwards the light of the objects while viewing.
Then, glue the batteries with the ear piece of the goggles and connect the LEDs. If necessary, you can add the switch to on and off the LEDs. Finally, examine how it works. If the image is dull, add the red gel to the outside and blue on the inside. The additional LEDs are used to provide the extra illumination in the complete darkness.