Has anyone tried doing this? Reducing battery lifetime is a recognised problem with 405s, and I came across a website which shows how to change the battery. I'm reasonably adept with a small screwdriver and a soldering iron, so I'm sort-of confident, but I wondered if anyone had any real experience.
For anyone interested, the website is:
http://www.akku-wechsel.de/shop/forerunner-405?___store=gb&___from_stor...