

Go to the /Applications/ directory and right-click on “Install Mac OS X Mountain Lion.app” selecting “Show Package Contents”.Download OS X 10.8 Mountain Lion from the App Store.Download OS X Mountain Lion and Extract the DMG File If you already have the Mac OS X Mountain Lion install DMG extracted, skip this first set of steps and jump directly to making the bootable drive below. We’ll walk through the process here, but don’t forget to check OS X 10.8 system requirements for the destination Mac before beginning. Repeat steps 3–5 for each remaining partition.By creating a bootable install drive, you can perform clean OS X 10.8 installs, install it on separate partitions, and install OS X Mountain Lion on Macs that don’t have internet connections. Restore from a disk image: Click Image, choose the disk image you want to copy, then click Open. Restore from a volume: Click the “Restore from” pop-up menu, then choose the volume you want to copy. This is the volume that is erased and becomes the exact copy. In the sidebar, select the volume that you want to restore, then click the Restore button. See Partition a physical disk in Disk Utility on Mac.

The destination disk must have as many partitions as the disk image, and each of the disk’s partitions must be at least as large as the corresponding partition in the disk image. In the Disk Utility app, select the disk in the sidebar, click the Partition button, then partition the destination disk.

The disk image’s volumes appear as disks in the Finder.

In the Finder on your Mac, double-click the disk image to open it. To restore a disk image with multiple volumes to a disk, you must partition the destination disk, then restore each volume individually.
