Hi Himark,
homing without home switches? So to say, as a manual procedure?
Before I equipped my "prototype mill" with limit switches, I did it as follows:
(I was running on soft limits)
- first, switch the coordinate DROs to "machine coordinates"
- then, jog the machine to the desired reference position (you can define the individual reference position of your machine in "Config - Homing/Limits - Home Off.")
- press "REF ALL HOME", and the "Home Offset" will be written to the (machine-)coordinate DROs.
- switch off machine coordinates to see again the work coordinates.
--> The Limit switches must be unassigned in Ports and Pins, and "Auto zero" in "Homing/Limits" enabled.
On very small machines with low torque drives, it might also be possible just to drive against the mechanical limits until you reach the soft limit, but this is not nice to your machine.

But on the other hand, it's really worth the trouble to put limit switches on the machine, because it saves much time and.... IT'S AUTOMATIC ;-)
regards,
Konrad