How can I adapt a 8-WFDFN Exposed Pad to a breadboard?
You'll need an 8-WFDN adapter, which is a different footprint than the SOP8/SSOP8/TSSOP8/SOIC8 footprints on the adapter you linked. Probably not easy to find - it's not a footprint commonly used by hobbyists. If you do find one, it may well end up costing more than buying similar components in another package. 

If you think you can solder it (which might be very tricky without a reflow oven) then you could design your own adapter using EAGLE or similar - the footprint should be available for an existing part, and all you need to do is hook up the relevent pins to rows of 0.1" holes. There's companies in China which will do 5x5cm PCBs for about $10 (I've never used iteadstudio, but I've read positive reviews on the web). SMD to DIP adapters really are among the simplest boards you can design.

Your last option would be to solder leads to it "dead bug" style. It is an absolutely tiny chip though. The smallest SMD components I've soldered were MSOP packages, which are 50% wider than the WFDN package and also have leads (much easier to solder). Even then I don't think I'd have been able to do it without a microscope. I suppose if you've got the chips anyway it's worth a try, but don't be surprised if you destroy them all attempting to solder them.