手(て)こずるto have much trouble, to have a hard time, to not know how to handle

やんちゃな子供(こども)の躾(しつけ)に手(て)こずる。

Having a hard time disciplining a mischievous child. {to have much trouble, to have a hard time, to not know how to handle}

先生(せんせい)が泣(な)き喚(わめ)いている生徒(せいと)に手(て)こずっています。

The teacher is having a hard time dealing with the student who is crying and wailing. {to have much trouble, to have a hard time, to not know how to handle}

交渉(こうしょう)に手(て)こずっている社員(しゃいん)が冷(ひ)や汗(あせ)をかいています。

The employee who is having a hard time with the negotiations is breaking out in a cold sweat. {to have much trouble, to have a hard time, to not know how to handle}

コンピューターの組(く)み立(た)てに手(て)こずった結果(けっか)、丸(まる)二日(ふつか)もかかった。

As a result of having much trouble assembling the computer, it took me a full two days. {to have much trouble, to have a hard time, to not know how to handle}

社員(しゃいん)：「その問題(もんだい)には手(て)こずったけどさ、まあ何(なん)とかなって良(よ)かったよ！」

Employee: "I had a hard time with that problem, but I'm glad it somehow worked out!" {to have much trouble, to have a hard time, to not know how to handle}