In what ways does the party show rebellion against The Combine and/ or Nurse Ratched’s control over the ward?

They refuse to do their afternoon work during the Wolrd Series because they want to watch, and Ms. Ratched has refused their request.

Ten of the men go on a fishing trip with McMurphy. They take the boat without permission and have a wonderful time.

The "party", itself, occurs on the evening McMurphy is set to escape, so he wants to wait until morning. The men break all the rules. The men drink (get drunk), party, and break into the medicine room. The girls are their to spend the night with the patients, Specifically, Candy is there to spend the night with Billy.

In essence, the men break all the rules, completely undermining Ratched's control over the ward.