Pull the stringers together using the new Bessey clamps you just bought then from the underside of each tread secure the tread to the stringer with the Kreg Pocket Hole Jig you have just bought and then flush cut the dowels with the Japanese flush cut saw you have just bought.
THAT'S WHAT I WOULD DO :D:wink::D
Of course if you managed to find access a bit tight then a Festool C12 would soon fix that :p
Gotta protect that marriage
