Clutch slave cylinder bleed nipple
Remove the plastic cover cap from the top of the transmission. Put a piece of tubing onto the bleed nipple, then put the other end of the tubing into a container to catch the expelled fluid. When you loosen the bleed nipple (using a 13 mm open end wrench), the entire stem will turn. Half a turn should be enough to induce good fluid flow.
Note: This is a '91 model. Later models have a different slave cylinder that is covered by a rubber boot.