Homing, when I go to move and select get position the Y axis is at 460. How do I clear it?

It may be wise to question how you’ve arrived at what the Engraver has counted as (0,460) and why it’s “wrong”.
For Standard GRBL, the code is $RST=#
Enter it in the Console window and it should reset everything there to zero but you may want to hold off for a bit. 
Open the move window and set the jog distance to 20 mm and 500 mm/minute and confirm that the the jog arrows behave as expected.
If you have selected the origin contrary to how the NeJe3Max is set up the jog arrows should misbehave. If the arrows behave properly, then go for it.