I'm in the process of doing this myself as well. If you paste them over to Word and than scale them to 3.41" x 2.44" they fit nicely on a card without any of the boarders on the cards overhanging the edges. They also fit four to a page (isn't that just awesome convenient?)
Than just print them and cut them out.
I than have been using Elmer's glue to adhere them to the card (the slightly smaller size allows you a few millimeters of play when centering them on the card). That way you don't have to slip them in and out of sleeves constantly. Hard shuffling might crack the glue adhesive over time, but if you're gentle on shuffling it isn't an issue and even if they do? Simply glue them back on.