its just a little roll pin, you can pop it out with pliers to get the screw out as needed.. I used to know what the purpose of that pin was, but can't recall now.. think it was for alignment of the starter / housing to get it evenly spaced within the cup so the starter dogs (2 of them) would center in the cup and evenly distribute the force.. However, you do not need to remove that to service the starter unless the problem is actually the spring itself - More often when the recoils do that it is because the rope is fraying and doesnt reel back in evenly to the pulley - if you have starter off, and observe while the rope is retracting, bet you find the rope binds between pulley and housing.. - rope can be replaced on most of them without removing the starter pulley. Otherwise, also inspect for alignment of the recoil over the starter cup (be sure the pulley doesn't rub on the starter cup) and check that blower housing is fastening down evenly on both bottom sides - if you tighten down one side all the way before tightening the other it can twist the housing a bit and cause recoil binding, as well. I would actually recommend NOT lubricating the recoil hub and especially not the starter dog mechanism - they require friction to work properly so lubrication that seeps in defeats the purpose.
If you check all those points above first you may not need to disassemble... but if you do, I recommend just cleaning and no lubrication.