you may be able to look down in with a flashlight, using a long thin screwdriver push the rod back towards the clutch side and get the actuator back down in ?
If that doesn't work, you'll need to remove the peg, kicker and clutch cover, then undo the 5 bolts and springs holding the pressure plate on, move it out just a little to allow you to push that rod from down in the actuator hole with the skinny screwdriver, and drop the actuator in.
when reinstalling the pressure plate bolts/springs, tighten only to the 4.3 ft. lbs. spec, or you'll strip or break them.
really, even hand tight with a large phillips screwdriver is enuf, they're not at risk of backing out with all that spring pressure on them.