If you are staying anonymous you need to send five letters - real letters - not emails.
1 letter to an elder - any elder. Saying you disassociate/don't play by their rules and why etc.
4 letters to rank and file members of yours and/or a nearby congregation adding the sentences "hundreds of these letters are being sent in the area. (Don't tell them "the area" is the whole country!) Do not pass them to the elders."
They likely will immediately show one of their elders who will contact fellow elders, the branch or CO.
So only 4 or 5 letters will likely be handed in but they will think that there are loads of letters still out there not being handed in. It will send them crazy. They may even announce that if you have received a letter then hand it in.
If you are really cool post a letter to yourself and hand it in saying you received it in the mail - which of course you did!