Go to the Grailum Core wallet page and download the latest Mac OS zip file.
After downloading the file to your Downloads folder (/Users//Downloads), run it by double-clicking its icon. OS X will open a Finder window for you to drag Grailum Core to your Applications folder.
The first time running Grailum Core, Max OS X will ask you to confirm that you want to run it:
You will be prompted to choose a directory to store the Grailum block chain and your wallet. Unless you have a separate partition or drive you want to use, click OK to use the default.
Grailum Core GUI will begin to download the block chain. This step will take just a few minutes on a regular Internet connection. During the download, Grailum Core will use a significant part of your connection bandwidth. You can stop Grailum Core at any time by closing it; it will resume from the point where it stopped the next time you start it.
After download is complete, you may use Grailum Core as your wallet or you can just let it run to help support the Grailum network.