Reformatting A Macbook (With a broken disk drive)

If you have another computer, you could most likely boot the cd through connecting the 2 together via firewire and holding down C on boot.

 

If you have an external hard drive then you will most definitely have one.
Here's a pic of one just incase you don't have one and go and purchase one.



If you want to do what I suggested, I would purchase a FW>FW cable for faster speeds; and try to google up some questions you may have, cause' this is just off the top of my head

 

Using another computer and a FireWire cable in order to see and use the information on the hard drive of another is called Target Disk Mode- you can get all the info you need about it and how to do it in the Apple documentation about it here. You should have no problem doing the install that way.

EDIT: I know of no other way other than to temporarily attach an externally cased DVD drive.