i recently had my alignment & camber done for my 997.2 TS. my car is completely stock standard from factory.

rear camber was adjusted to approx -2 degrees. both front & rear toe was slightly in

question. the tyre shop that i visited says that front camber for my car cannot be adjusted. reading was approx -0.5 degree. how do i adjust the front camber?
was reading on 6 speed that a more -ve front camber setting would give better handling & cornering. I hope to get -1 degree with my stock suspension setup. Is that possible?

thank you