i have an 2002 infiniti i35 and i got in an accident and need to replace my headlight lens. my hids work 100% fine just need to know how to change the right headlight len. my len have scratches on them. please someone tell me.

 

I'm assuming it's not CRACKED, but simply scuffed up pretty bad, so you will most likely not have to replace the entire headlight assembly. Otherwise, do a search for headlight restoration products to remove scratches and hazing. You will probably have to do some sanding if you have any deep gouges in the plastic.
There's all kinds of products out there like this: