Any change in lifestyle needed when basal cell carcinoma diagnosed?

Usually not many: Its good to have safe sun practices, including sun avoidance particularly during midday and frequent sun screen usage.

Sun avoidance: Although it is difficult to reverse damage already done, you can prevent further damage by sun avoidance, use a sunscreen of no more than spf 50, reapply frequently, wear a hat with a brim, and avoid the sun. Please see a good plastic surgeon or dermatologist. Be well.