How to get there
Click the Smart Shape Tool 
.
What it does
The Smart Shape Menu allows you to flip
the direction of slurs.
- Shape Direction: Flip · Automatic · Over ·
Under. PrintMusic makes intelligent decisions about slur direction,
based on whether the attached notes are above or below the middle staff
line. When you transpose music or change the key, slur directions are
automatically changed, without requiring any action on your part. However,
there will be times when you’ll probably want to change the direction
of individual slurs that are attached to notes. This you can easily do
using the Direction submenu.
The Direction submenu offers you four choices: flip the
currently selected slur, place a selected slur over the entries; place
the slur under the entries; or use automatic placement. Flip and Automatic
have keyboard shortcuts of command-F and command-shift-F respectively.
