1 hr. drilling out rivets in the rear spar that shouldn't have been riveted and test fitting the top skins.

A video showing how you remove a pull rivet.  You'll note that I allowed the drill bit to go all the way through.  Some recommend you only drill to remove the head and then use a center punch to remove the rest as to not damage the hole.  I did do that on some, but often the rivet would not just pop out.  I didn't find that putting the drill all the way through did any damage (e.g. enlarging it).

And the top skin fits perfectly and it's nice and flat!

NEXT SESSIONS:

1. Rivet landing light pieces.
2. Bolt down jigs after checking level again.
3. Flip assembly.
4. Test fit of bottom skins (don't forget stringer!) for fit and levelness.
5. Test fit of pitot assembly.
6. Flip assembly.
7. Remove top skins and rivet ribs.
8. Flip assembly.
9. Rivet bottom skins.
10. Flip...
11. Wiring in.
12. Air lines in.
13. ...