Panerai Crown Guard

[GCPlati]

Question related to service...

After several years of heavy use, my old man is giving me his Panerai 299. While generally in good shape, the crown guard is pretty loose and jiggles around. Certainly not useful any more in preventing ingress of water. Is there a way to tighten it myself using inexpensive tools I can buy online, or would you recommend either bringing it in to an AD for service/sending it to Panerai. All else being equal or nearly equal, I'd go with the lowest-cost option.

Thanks!