Looks like a CB350F cover and I did two just recently. I used a set of small thin needle nose vice grips to push back the spring/washer on the stem and take the pressure off the split pin. I then used a second set of linesman pliers with flat jaws to push the split pin flush with mounting post. A small drift or pliers to grab the pin to then to push/pull out the remaining split pin from the post.
You can sometimes reuse the old pins, if not Princess Auto sells a box of various sized split pins that can be used to replace the original ones.