You will need:
Repair Putty aka Mighty putty - I got mine at Dollarama for 2.00
Small Phillips Screwdriver - not sure what size...
Black paint - latex, whatever
Unfortunately I didn't get the idea to make this repair an Instructable until half way through the process so you'll have to make do with the pics I took.
Step 1: Isolating the broken piece.
Next you need to detach the actual cup from the broken piece (looks like an inverted Y).
See the pictures for explanation.