Step 1: As always, collect your materials...
1. A suitable IC. I pulled mine off a card that says "Super Serial Card," and my dad, a former Apple technician, says that it was for connecting a printer to an Apple II. It's easier if they are in a socket so you don't have to desolder it.
2. A magnet. I used some old magnet strip that I had lying around. I would recommend finding something a bit stronger than that, simply because it will hold more. Make sure that you find a magnet that fits under your IC, or find an IC that fits over your magnet.
3. Glue. I used CA (superglue), use whatever you want. Superglue I know works, contact cement will almost definitely work, epoxy might work, Elmer's School Glue won't work.
4. A spacer (if necessary). You might need something to raise the magnet up. A bit of plastic, a popsicle stick, cardboard, whatever. You're creative, or you wouldn't be reading this. Figure it out.
5. A fridge. Why make a magnet if you don't have a refrigerator to stick it on?