Change unit's movement type in game using triggers?

Change unit's movement type in game using triggers?

Does anyone know how to change a unit's movement type in-game using triggers? or do i have to find some complex alternate methord?
(Or simply making the unit able to pass through other units for a set time, then go back to normal)

Well, you can let them walk through objects with Unit - Turn Collision On/Off...

Thanks very much, that worked.