[dsraven]

if the levers on the outside don't wanna move, first try putting the truck in a position so that there is no strain on the gears inside the trans. like roll the truck back and forth a little and then block the wheels so it is roughly in the middle of that fore to aft movement. this takes the strain off the gears inside so you can shift them. you can check if the stress is off by trying to turn the driveshaft it you have an open driveline. it would have a little slop and not be held tightly. you could also push the clutch arm while trying to shift as this should also relieve the strain on the gears and allow a shift to be easier but that could be a two man operation. Iusually use a set of groove joint pliers for a little extra leverage on the shift levers so I don't skip past neutral into the next gear so easily. don't force the operation though as this can chip the edges of the synchro gear teeth