Setting Roller Jewels
I have had my troubles in the past setting loose roller jewels, but as time passes on, we all should improve on our methods in doing the job better and with greater speed.
In my experience, I have had different gadgets, which upon giving a fair trial, have discarded and I now rarely use any of them.
In the replacement of the roller jewel, I usually use the above method, especially in the larger sizes. Bear in mind it takes a little practice and good judgment, and extreme care should be used not to get balance too hot.