If you want to maintain appearances, this is the best:
1 - Find a foreign language congo in your general area like Spanish
2 - tell elders in old hall and friends that you are going because you want to learn the language and the schedule is better for your job.
3 - Go to elder in new hall and tell them your are moving.
4 - While your records are being transfered, attend a few meetings, mosly weekends
5 - Once elders tell you that you are officially transfered, immediately start missing meetings more and more.
For the old congo, you are the brother who left for another hall. On the new congo, nobody really knows you anyway. It's helpful if the new congo is a foreign language congo, because your old hall won't even expect you to see you at conventions.