Polar finder collimation

[ARP1954]

Hi

The older Celestron CG5 mount had 3 retaining screws that allowed the polar finder scope to be rotated 360 deg when mounted. Newer finders are screw fit but what to do if once the finder scope is inserted and tightened only to find that the vertical axis of the finder display is not at 90deg from horizontal plane?

The 3 screws only allow for centering the reticule and I would need to disassemble the finder to rotate the reticule holder but how can I be sure that when put back together it will be correctly aligned?

I am referring to the skywatcher HM5 for the EQ3/5 mount.

Thanks in advance