The capability to swap the optical drive and replace it with a second hard drive (or battery in some cases, etc) is called Ultrabay. The E430 specification sheet says that the optical drive is fixed and can't be removed. That's one of the features they cut from the Edge series for cost reasons.
That said, your E430 does have an mSATA slot, so you might want to check around on the web and see if other folks have had success with the Intel 310 mSATA 80gb drive (if you can get it in stock) - that would let you boot from the mSATA SSD and retain the 500gb drive for storage and apps. There are other manufacturers of mSATA drives - just using the Intel as an example as it's mentioned here often. Good luck!
I just received my E430 in the mail today. And contrary to what the manual says the dvd drive can be removed, when you remove the access panel you'll find a single screw holding the drive in place. Whether or not it can be swapped is an entirely different matter.
Unfortunately I was unsuccessful installing the 2nd hard drive caddy made by Newmodeus that I previously used in the Edge 14. While the caddy and the dvd drive share identical dimensions the msata connector on the caddy is few millimeters to high.