Possible to restore Snow Lion from external clone *without* install disk?

[Queue Cumber]

Is it possible to reformat/erase my original internal hard drive on Snow Leopard (10.68) working from my clone on an external hard drive *without* using the OS installation disks?

I am just trying to erase and restore the original drive (which is running sluggishly and Disk Utility tells me it cannot be repaired so needs to be reformatted) but after several years have lost my install disks. I already successfully created a bootable clone on my external drive, but what is the next step to reformatting the original drive and restoring from the external clone? Can I just erase the internal drive and re-clone everything back from the external drive? I hate to have to pay for a replacement disk just to do this, especially when I'm probably going to upgrade to Snow Lion soon anyway.

Any help would be appreciated!

 

[Intell]

Once you have your external drive cloned from your internal drive, restart and press and hold the option key. The external drive should show up as a bootable drive. Use the arrow keys to select it then press enter. This will start your Mac up from the external drive. It will be slow, but it will work. It should be exactly like your internal drive. Just use Disk Utility to erase the internal drive and recopy the contents back over to the internal drive.