Grub Screws to set Clutch Toggle Lever Height

[Jamie]

I am starting on the clutch for my Ruby and notice that it has had grub screws inserted where the heel of the toggles has worn a groove in the plate. The screws are now worn and need replacing. However, how do you actually use them to set the height of the levers? Unless I am getting confused, the heads of the grub screws are covered up when the clutch is assembled, meaning that you cannot use them to adjust the height. Is it simply a case of guessing the correct setting, bolting the whole thing together, measuring the height and dismantling it again to adjust, repeating this until they are correct? If this is the case, does it need to be on the engine to get the height or can it be done on the bench?

Regards,

Jamie.