Well, looking at the first link, it should be really easy to open the jump rings holding the beads together and get them apart. Unfortunately, from what I can see, they have a loop as part of the setting on each end. So…you would have a loop on the ‘top’ to attach to a jump ring or a bail that would be on the necklace, but you would also have a loop on the ‘bottom’. You could use this to just have a coordinating color bead hanging down there, I guess.
It looks to me like each eye has a loop on the “top” and “bottom” (oriented as a pendant), with a jump ring linking each to it’s neighbor. The jump rings are no problem - take two pairs of needlenose pliers, hold each side of the jump ring and pull one and push the other so the ring opens at an angle to the plane of the ring. Wait, it’s easier to show you than to put it into words: Opening Jump Rings.
So that’ll let you separate them and then you can use the jump ring to hang it from a necklace. It does, however, leave the loop on the bottom of the eye open. I’m not sure what sort of metallurgy you’ll need to take care of that. You can try grasping one with your needlenose pliers and bending it back and forth and see if it’ll snap off. Use a nail file or fine grained sandpaper to smooth any rough edges.
Or (and this is what I’d do, personally), you can add another bead in a matching or coordinating color or metal. Hang it from the lower loop (via another jump ring, probably), and no one’ll know that wasn’t part of the design!
