If this is a 355 series truck the bell housing should have a large cover on top that can be removed. If I remember correctly the brake and clutch pedal pivot on some bearings on this top cover. Take the cover off, if the input shaft has a removable drive on it there will be 6 bolts holding the splined hub to the input shaft.
There is also a Allen head screw that holds the pilot shaft into the pilot bearing. Loosen that set screw and push the pilot shaft toward the transmission, remove the six bolts that hold the splined hub to the input shaft and remove the hub. Then all you have to do is remove the bolts from the pressure plate.