Quote Originally Posted by TazX View Post
... I have been informed, however, that I should use the left extruder for printing with PLA...
That's nonsense. You can use whichever extruder you prefer. The software defaults to the right one, that's all i.e. right = T0 (default) and T1 = left


Quote Originally Posted by TazX View Post
... am unable to see where I can change that setting...
In Makerware. If you have chosen the dual replicator as your machine you see a button on the left your screen marked 'object' (should be below 'scale'). Click on your part, then click on 'object' to choose the extruder you want.

In the main toolbar at the top click 'edit' and then 'settings' to choose colours for your extruders.