I need help figuring out how to wire up an Aube T1033. I've attached a .pdf depicting my existing switch box. I want to replace the right hand switch with the T1033. The existing wiring is more complicated than I expected.
Something is wrong with your diagram. You describe a "3-way" setup where two different switches control a single load. For a functional three-way with standard, dumb switches, both switches must have three connectors. On each switch, one of the connectors is labeled "common" and might have a different color screw. The switches channel "hot" onto one of two travelling wires - when the switches put hot on the same wire, the load is energized.
If you have a standard 3-way setup, then you have the wrong Aube part. The Aube 1033 does not support a remote switch.
The appropriate Aube part for a a "3-way" application is the TI072-3W. This switch must be installed in the box which contains both the supply hot/neutral and also the load wires. Your diagram doesn't show what goes to which boxes...
The Aube allows you to use a single pole switch in the remote location; if you want to re-use an existing 3-way remote switch, you jumper common with one output. It's possible you could replace your left-side switch with the Aube TI072.