clean out the edge of bezel that sits on back case either with adhesive remover that is safe on plastics or by scraping with tool... it has little grooves that will be full of the old adhesive. clean the back case where it will join the bezel... it has small plastic pieces which fit into the grooves.
I have used silicon and also hot glue (low temp version)
or apply small amount of adhesive which is flexible/safe on plastics to each of the grooves (small=tiny) put bezel on rear frame.
I don't know where you live so I don't know what product to recommend- another reply to similar question has a link to his recommendation (sorry can't seem to paste link here) search "what's the best adhesive for fixing chrome bezel to back housing?"
DONT use superglue...it'll melt your brand new housing!