The following method will allow you to clone the eMac with all your goodies on it to all the other eMacs. The following will use the OS X Disk Utility (free and very good) without needing to disassemble any hardware or need to doing anything crazy
You will need:
a. An OS X install Disc
b. A firewire cable (6 pin to 6 pin)
c. eMac A - the Mac that you want to copy to the other machines
d. eMac's B through K that Mac's that you want to have like eMac A
This is one of several methods, but this will not require the least equipment:
1. Take eMac A and boot to the OS X installation disc.
2. Prepare [eMac B] by booting it into Target Disk Mode by holding the "T" key after hitting the power button. (you should see a firewire symbol floating on the screen)
3. Connect eMac A to [eMac B] via the firewire cable.
4. On eMac A click on the "Utilities" menu at the top of the screen and then click "Disk Utility"
5. On the left side of the Disk Utility screen, you will see the internal drive eMac As well as the drive for [eMac B] which will appear as a firewire drive. Select the [eMac B] drive and click the restore tab on the right pane of this window.
6. Drag the drive icon for eMac A to the source box.
7. Drag the drive icon for [eMac B] into the destination box.
8. Click the "Restore" button at the bottom lower right-hand region of the window.
10. Once the restore is complete - disconnect [eMac B] and turn it off using the power button and turn it back on... test out your newly cloned Mac!
11. Follow steps 2-10 on [eMac C], [eMac D], etc...