Relays 1 and 2 are intended to be used for controlling the VFD or Speed Controller and are intended to activate the FOR and REV signals (US MODE) or the ON/OFF and CW/CCW (INTernational MODE).  But if you do not need to control the VFD, but intend to use them for general-purpose, it is doable.  Here is what you have to do:
Go to Motor Output and unassign pins 14 and 16 on port 1 from the Spindle Control.
Set Jumpers for US/INT Mode to Jumper1 = INT and Jumper2 to US.
You can then pins 14 and 16 for activating Relays 1 and 2.