If you are really worried, send it to rob and he can do it for a small fee. Otherwise I suggest taking the reo apart so you don't end up filing the button. I used a flat ....... file on mine. And before filing the reo, I filed a candle. The wax helps the file not get clogged up with aluminum. I went a step further than I probably needed. But I remove the center post and gaskets from the 510. I suppose you can just put a water of tissue down in there though. Wouldn't want a short or to have metal filings end up in your liquid.