Justin played the role as big strong man and cut the corks in half for me. He looked online for tips on cutting up the corks and found that regular corks are not as easy to cut.. and they suggested using a saw. However, the corks I gave him were corks from Barefoot Wine, and they were easy to slice right through with a knife.
I used some E6000 glue to attach the cork halfs to some ceramic magnets. I let them dry overnight and put them on the fridge the next day. They look fantastic and finally all my magnets match perfectly.