You will need the following tools: a hammer (the dinky hammers are great for the job as they allow you to put just the right amount of pressure on the eyelet), an eyelet setter, a hole punch to match the size of your eyelet, and of course your chosen eyelet. A self-healing mat protects your surfaces from getting damaged, but you could of course use an old chopping board or similar.
An important point to note is that you should not attempt to attach your eyelets if you have delicate embellishments on your card, instead choose an appropriate stage - for example in this case it was appropriate after embellishing with items beneath the tag, but before finishing with final embellishemtns that may have been damaged by the process of attaching the eyelets.
Now you need to make a hole in your card the same size as the eyelet you're using, Common sizes are 1/8" and 3/16". The hole is made using the hole punch, which you place exactly where you want the eyelet to be fixed. This punch has a round, hollow tip at one end that cuts a hole through the paper. Place the sharp edge of the punch where you want the hole to be and then give it a tap with your hammer. You could also use a long reach punch the size you require.
Turn your card over and place the eyelet setting tool against the straight end of the eyelet. Tap the end of the tool with a hammer which will make the tube flare out. You could leave it as it is, but if the edge is a bit rough you can finish setting the eyelet with the finishing tool. This gives a smoother finish to the back of the eyelet. The tool has a concave end that you place over the backside of the set eyelet. You tap it with the hammer just like you did with the setting tool.
Note - The sharp eye may have detected that I placed the "H" and "B" (Happy Birthday) Tags (from the Hot Off The Press Cardmaker's Jewel Creative Pack) in incorrect order. Let's just say that I did that to illustrate the importance of ensuring the correct layout before making irreversible changes