Focuser advice please

[Astronovice]

I am in the process of building and fitting a MyFocuserPro2 electronic focuser to my TS APO 90mm triplet. The underside of the focuser has 6 counterbored screws plus a centre lock screw (see pic below). Can anyone advise which of the six screws can be removed and replaced with longer ones to allow me to mount the focuser support bracket please? The 2 centre screws are less recessed than the four outside screws.

[Pepper]

On my ed100 focuser the screws on corners held the mechanism in.
I replaced some to hold my focus motor bracket.
They had rubber o rings under there and were easy to lose.

[Astronovice]

Thanks Steve, hopefully my TS is similar