Why not partake of the memorial emblems? I promise you that this will cause great consternation amongst the elders, after doing this they will, most likely , be quite happy to let you slip quietly away.
Persons partaking are generally recognised as being slightly nuts, play it for all it's worth!
If you must send in a letter and play by their rules,
Send them a letter that YOU disfellowship them for THEM for conduct unbecoming of a christian organisation. For added comfort a small ad in the local paper would cetainly get their attention. Nns7
I suggest bang the elder's daughter and don't tell anyone. I made a career of it, and derived maximum enjoyment therefrom...so did all the elder's daughter's.
Personally, I think banging an elder's daughter while attending a district assembly produces the most, er, bang, for the buck. Circuit assemblies are good for that purpose, too. But for maximum enjoyment, I recommend the district ones.
Best after all that to walk away with no notification of any kind. Just move out. No forwarding address. Just disappear. They can't ABIDE being ignored. It says to them that they're not important to you even the least little bit.