At the link that Achipmunk provided above, are 1938 and 1941 Shop Manuals. The instructions for removal/replacement should be the same for yours. Guide pins are referred-to for removal.
Those guide pins are invaluable for installation (and, safe removal). They not only set up the correct angles, but they allow you to more easily rotate the transmission shaft (from the ear) so that you can to line up the splines on the front shaft to the clutch (as noted by Pinetree, above).
Buy some bolts of the correct length and cut off the caps - these are your guide pins. The two bolts need to be long enough for the transmission to "sit" on them as you slide in the transmission (using a jack until the transmission is supported by the guides).
