肩の力を抜く

肩の力を抜く (かたのちからをぬく) means to relax and stop trying too hard.

Kana
かたのちからをぬく
Meaning
to relax and stop trying too hard
Japanese Example
面接では少し肩の力を抜いて話したほうがいい。
Translation
In the interview, it is better to relax a little and speak naturally.