As you can see there is what looks like a washer attached to the post which sits on the round circuit pad. You have to use a real hot soldering iron (45-75 watts) and heat it till the solder takes to it and flows to the round pad. You have to get the washer looking thingy real hot before solder will flow to it. If you don't use a real hot iron you'll be wasting your time and start heating up the board which is bad. The key is, real hot iron and do it quick. Look at the rivets first. If they look OK (no cracks or maybe just one) then it's probably connections elsewhere.
