I have a GME MT410G PLB. It has a battery life of 7 years which expires at the end of this year. A part of the regulations of registering with AMSA is that when you dispose of a PLB by whatever means, including lost or stolen, you need to notify them. Forms are available online, including change of ownership. You will need their name, address and phone number, along with the beacon details.
I'm not going to refurbish my GME, it costs over $200 and you only get a 12mth warranty. I'm buying the KTI, which has a 10 year battery life, is half the size and less than $300 to replace it.
When I do this at the end of the year, I will need to dispose of the GME, notify AMSA it is no longer active in my name and register the new one with them. From what I have researched, the ways to dispose the old one are; (according to AMSA)
Disposing of unwanted distress beacons
Option 1. Contact your local battery store to check whether they disconnect and dispose of beacons. ...
Option 2. Contact your local maritime safety agency. ...
Option 3. Check the beacon manufacturer's instructions, they may provide instructions on how to disconnect the beacon battery.
This is the physical disposal, de-registering still needs to occur.