Breaking into is a commonly used term, but there are several synonyms that can be used instead to convey the same meaning. One possible synonym is "intruding" which means to enter or gain access to a space without permission. Another synonym is "penetrating," which implies a forceful entry. "Trespassing" is another synonym that refers to entering a restricted area without authorization, either intentionally or unintentionally. "Infiltrating" is another synonym which means entering secretly or surreptitiously in order to gain information or access. Finally, "breaching" is another synonym and it refers to breaking through a barrier or obstacle to gain access to a restricted area.