The spindle cannot be jogged as you would the table and quill. It is run under program control. Not hard to accomplish, however.
After you have booted the control and performed the axis reference steps according to the manual, hit the "Mode Select" key and select "C" for catalog mode. Type in a new program name and hit enter. Press the mode key again and select "Program". Type N10 and hit enter. Hit the "Event Type" key and select "M Function." Type M03 (zero three) and hit enter. Type S100, enter. Press the mode key again and select "Single Event". Press the green button. If you (or I) made a mistake, the control will tell you. The control may require you to have the drawbar clamped before it will execute the program. Reset will stop the spindle. If you are wanting to do some "manual" milling, you can select the jog mode and leave the spindle running.