you dont need to split the g/box and t/box, undo the 3 bolts and 4 nuts holding front cover ,remove lay shaft bolt, then undo the 4 nuts/bolts holding bell housing on and tap bolts out, bell housing will knock and wiggle off, you will need to remove box top and 3/4th selector to allow 3/4th synchro hub to slide off main shaft, synchro hub has a recess one end thats the end that must face 3rd gear when refitting