[roll] up {one's} sleeves

to get ready to do hard work or tackle a serious challenge

With the deadline approaching, the team rolled up their sleeves and worked late into the night.
She rolled up her sleeves and started cleaning the entire house.
The workers rolled up their sleeves to repair the damaged bridge.
He rolled up his sleeves to face the tough negotiations.
The students rolled up their sleeves to finish the group project before class.