the headlamps are probably the same setup as all 7th gens.. so heres a link.. Difference of Stock vs HID Celica headlamp pictures
if you look at the first picture in this thread.. theres like a rusted looking thing.. well thats the part where you'd stick a philips screwdriver to.. the "bottle cap" looking thing that Lee_H was refering to..
then you just turn it.. not sure if counter or clockwise is to make it down...
if your strong enough you coud even just turn it with your hand but it starts to hurt after awhile..