"To be in sb's hair" is a colloquial expression that means "to be a bother or hassle to sb." So, to "[be/get] out of sb's hair" means to stop hassling someone, or "leave sb. alone."
ex.
(reminder) "That assignment I gave you needs to be done by Friday, but don't worry, once I get it from you I'll be out of your hair."
(angry) "Okay! I get it already! Please get out of my hair about it!?"
(讨厌的感觉) "That Jim is so finicky, if he sees you do even one thing wrong he'll never get out of your hair until you fix it."
基本上这句话就是“不打扰你了”,但是比较口语,非正式用语。