Okay so defacing the coin of the realm has a great tradition, the suffragettes did it, so we should do it.
Firstly I make the coin nice and clean, sometimes I soak in white vinegar, polishing with silver polish is really good.
Then I sketch out the proportions of the EXTINCTION Symbol with a pen. Then place the coin on my anvil or another piece of solid steel, and use my cold chisel and a hammer to cut into the metal. If you use a block of wood or a bouncy surface you will find it way harder.
Previously I sharpened it up on a grinding wheel. Cold chisels are for cutting metal (when cold - hence the name) or stone etc.. not to be confused with wood workers chisel for cutting wood.
Then I use a centre punch to mark where the hole it to go and drill it out going as slow as possible with as much coolant-lubricant as possible. When drilling metal (or even wood) you really do not want your drill bits getting hot, they will lose their temper and then sharpness. I have bought a couple of hand crank pillar drills for this purpose. From doing workshops with electric and hand crank sewing machines we way prefer hand powered, so much better for learning and way less dangerous and noisy.
Then I put matt Humbrol enamel model paint into the cuts, to make maximum contrast with the polished surface. The ring illustrated above is from S&K fittings aka S&K CAMDEN, they where 8p each, way too much. there you go, please start a craze of Rebellious Jewellery making !!!