Through the vent tubes.
PS: After setting for a few months (if it hasn't been started regularly) I like to pull the distributor an prelube the system. I use the shaft out of an old distributor or remove the gear from an old distributor and the upper part that the rotor attaches to and attach a reversable drill. Be sure to not pull the
oil pump drive shaft out of the pump when removing the drill motor & shaft. Spin it for about 20-30 seconds counter clockwise.