I've got a tool kit for applying snaps that, sad to say, I haven't opened since I got it about 20 years ago (yikes!). Mine is a Prym, but Dritz has a lot of them. The tool looks like a pair of pliers. I have a kit with some adapters that can be stuck on the pliers to accommodate multiple sizes of snaps. If you check Amazon for "snap fastener" or "snap fastener tool", you will find several options.