If you want to be inactive and not be held to judicial action by any JW committee, just send the congregation you were last an active member of a letter saying you are exercising your legal right to leave the so-and-so congregation but that your letter of resignation as a member of this congregation is not to be regarded as somehow no longer in association with other JW's.
You are separating yourself legally from this congregation and reserve the right to join another JW congregation when you find one that you feel would better meet your spiritual needs. Since you are not breaking association with JW's you will consider any effort or threat by the JW elders to disfellowship you as reason to take legal action (as supported in the U.S. by legal precedents such as GUINN V THE CHURCH OF CHRIST OF COLLINSVILLE decision by the Supreme Court of Oklahoma, January 1989 and THE NORMAN HANCOCK LAWSUIT of Mesa AZ 1985) to defend your good name and reputation without fear of intimidation or retribution.