YOU SAID:

I have to go to change my clothes, before going to the party

INTO JAPANESE

パーティーに行く前に着替えに行かなければなりません

BACK INTO ENGLISH

I have to go change before I go to the party

INTO JAPANESE

パーティーに行く前に着替えなければなりません

BACK INTO ENGLISH

I have to change my clothes before going to the party

INTO JAPANESE

パーティーに行く前に服を着替えなければなりません

BACK INTO ENGLISH

I have to change my clothes before going to the party