Helmet Lighting, Help!

[TanskiTannero]

I am currently making a helmet from the video game Destiny, and I am needing to put purple lights in the helmet but I don't knowhow to fit lights in there. Does anyone have any recommendations on how I can achieve this? I do not have access to solder but I can if I need to

 

[Riceball]

An easy solution might be LED strips, you can buy battery powered versions but you'd obviously need to figure out a way to hide the battery pack.