Please note you must have access to the staff records to be able to do this, if you don't a manager on site will need to delete the user.
Deleting a technician can be done in different ways, I'll explain the process of both, but this is brief description so you can choose which method to choose.
You can delete the whole record, which will permanently remove the tech and you'll not be able to see him on any reports or retrieve any data once this is done, or you can mark the tech as left which will leave him in any previous reports but remove him from the clock in screen/clock card etc.
To permanently delete a technician, go into Set up> Staff records> Pick the staff record up by either entering the staff number or select the name from the drop down menu and click load, go into the technician set up tab and then hit the delete button (this will bring up a warning message, click yes) and save.
To mark a technician as left, go into Set up> Staff records> Pick the staff record up by either entering the staff number or select the name from the drop down menu and click load, from here go into Leaving details tab and enter a date left. After this go to the technician setup tab and remove the 'Shift' and 'Efficiency' and save the staff record.