Sounds like Huck Brakes. The bothe shoes are held to the backing plate by one 1/2" pin at the bottom. There is a circular clip that holds the pin. The hard part is getting the clip off. It has a narrow and a wide side. The narrow side is pried away from the brake shoes and the clip is slid towards the wide side. The narrow part should be identifiable by a bump in its middle. Use pliers to turn the pin until the bump is at the bottom, then use a screwdriver to pry off the clip and remove the pin. The shoe assembly will then fall on your head!
Make sure the truck is VERY secure on stands, as the only way to see these parts is to be on your back with your head directly under the backing plate!
Hope this helps!
