How i can change my color eyes if i have brown ?

Supposedly there is a procedure that can strip away pigment from eyes to turn them lighter, not the other way around, you can't make blue eyes brown but you can turn brown eyes blue. I don't know how safe it is or who can perform it, but it's been done in experimental trials. If you want to get it done, I'd look outside of the US. Russians did Lasic 20 years before it was approved in America, now it's a standard. If you have the money you can get it done (research Korea too, they pioneered breast implants and nose jobs before they were ever practised in america). Surgeons in Asia have been performing gender reassignment surgeries since the 70's, they know what they're doing. 

You can't.  You can mask them with contacts.