a. source an identical sticker or check if a computerized sticker maker can copy it
b. the paint behind the sticker is probably better than the exposed paint. if there is some peeling, the adjacent area needs to be polished to see if it can match recently exposed paint. this can get quite complicated.
same thing happened to my Audi, pero nung ipa detail ko nawala.... nag e mail yung detailer sa Audi at sinagot daw naman ang inquiry nila........sa Frankline ako nag pa detail sa 31 examiner st sa qc