Whenever a new Merlin version appears, Merlin will prompt you for an update. This can happen automatically on Merlin’s start up, or the next time you have defined in the preferences that the application should check.
Alternatively you can call the command “Check for Updates…” as listed in the Merlin menu.
In order for you to decide whether you really need this update or not, the release notes of this new version will get displayed.
Click on the button “Install Update” and the download will start immediately.
As soon as the download completes, another dialog comes up prompting you to “Install and Relaunch” Merlin.
Do so, and you will get your Merlin updated and restarted.
If having started Merlin directly out of the mounted disk image you’ve downloaded, there is no need (or a way) to update it. Just download a fresh new copy of Merlin from our Downloads or Updates page, mount the virtual disk image, copy contained Merlin application to your Applications folder and use Merlin from there. For an installation screencast please check this video.
UPDATE – May 2013:
Some users reported download issues or incomplete application package after automatic update. In those cases please download the update manually and use following alternative link instead: