Installed LEDs into my Optimus Prime helmet today. =D After the helmet and LEDs sat in my dresser for over a year… 

1. Get lenses from a pair of sunglasses
2. Burn a hold through the lens using a hot nail (and a pair of pliers to hold the hot nail! =P) You can heat the nail with a blow torch like I did.. or use a gas burning stove.
Disclaimer:  BE CAREFUL and don’t do this if you are under 18 without adult supervision

3. Place LED through hole and using a hot glue gun carefully glue the LED in place. (I bought my LEDs on ebay with a battery pack.. Easy.. cheap..I’m too electronically challenged to wire them myself.)

4. Using your handy dandy hot glue gun to glue the lenses inside the helmet positioning them where you want. =D This is the trickiest part in my opinion. 

5. Using vecro strips… Glue the velcro into the top of the helmet and wrap the battery pack up.  There is a perfectly large gap up top towards the back of the helmet. Make sure the on off switch is facing the inside. (You could glue the battery pack directly but then good luck changing the batteries.)

Tis super easy and YES you can see out of the helmet with no problems! The LEDs are still high in the helmet above your eyes and the sunglasses block a lot of the light. Now seeing through them at night is another story…