Easy enough. Follow these steps:

1) [SETUP] [inputs].

2) turn wheel to right until you see "FWIRE in 1"

3) down arrow

4) turn wheel to right until you see "FWIRE in 2"

The main inputs 1&2 are now set up for FWIRE 1/2. So now, lets connect these to the outputs 1&2:

5) [outputs]

6) down arrow once to select (highlight) the first two outputs

7) turn wheel to left until you see "FWIRE in 1" & 2.  These are the inputs you selected above.

Job done.