phrases about change of attitude

Iron out

To resolve issues

“Kamiya-san and Higuchi-san have to iron out their differences now and agree to cooperate on the new project.”

Smooth over

To ease tension, to calm

“The customer was quite upset with the salesman but the supervisor was able to smooth it over.”

Hit the ceiling

To lose one's temper

“Miyuki-san's boss hit the ceiling when she told him she was taking a long honeymoon."

Note:“Hit the roof” is a variation of the above phrase.

Lose it

To lose self-control

“Tanaka-san lost it when he heard he was being replaced by a young female MBA.”

Come around

Change one's mind

“Though Ando-san disagreed with hiring a new designer, he'll come around when she sees how great her work is.”