This page describes the new auto plugin updater functionality and what you need to know to use it.
Since MyPet 2.3.0 (Premium: 2.3.5 or D1) the auto updater is part of the plugin.
By default the plugin checks for plugin updates but doesn't download them.
You can enable the download by activating it in the config (MyPet.Update.Download)
Premium users have to set a download token in the config (MyPet.Update.Token) that authenticates the download.
The token can be found on the download page of the MyPet website.
(login & an activated premium key required)
Just reload/restart the server and the plugin will automatically check for updates and download it if there is one.