I don't know where else to post this question. If there is a more appropriate section someone please let me know.
A friend of mine asked me to change the battery in this watch. The case back looks like it should just pry off but I do not see any visible slot around the edge to slip a tool. I don't want to scratch it up needlessly. I tried screwing it off using friction like on many pocket watches without success. Anyone with previous experience changing a battery in one of these?