— To upgrade OSX 10.4 on a iBook G4 and PowerMac G4 (both running Tiger) to Leopard 10.5 with only a DMG and USB drive —

– Download/Install: Carbon Copy Cloner at [link:]http://www.bombich.com/software/ccc.html[link:]

– Copy the DMG to the laptop

– Connect a USB drive WITH external power source to the laptop

– Using Disk Utility: Erase the drive

– Open “Carbon Copy Cloner” and select the DMG of the install disk

– Select “Use block-level copy” “Erase drive”

– Click “Clone”

Once the clone is complete, reboot the Mac and perform the open-firmware changes mentioned in this post. You should then be able to install from the external USB drive like it was the actual DVD.

**NOTE** I do NOT endorse stealing software. I obtained my DMG from our Apple Enterprise License at work and downloaded it directly from them.

Once you see your new OS you will need to reset your firmware so it doesn’t try and boot from the USB drive anymore.

– Reboot the computer and press:
This resets the firmware to the factory settings.

Keep holding this until you hear three “Bongs”. Once you release, the Mac should boot normally into your new OS!