The Woodward manual(s) are pretty clear how to enter valve stroke mode, but it leaves the user only being able to move the valve incrementally with the Adjust ("ADJ") arrow key. This allows an exact valve percentage to be entered. A warning but an obvious one is when a value is entered, the control will step (not ramp) the valve actuator output to this value.
IMPORTANT: As for any valve stroking with a second generation 505, the Emergency Stop discrete input (terminal 12) must be energized throughout this procedure. In many cases, this requires installing a temporary jumper.