I suggest you mark the holes from your old dash (assuming you have the old dash) they fit like a glove on your foot at the best of times but you can't go wrong using the old holes as a temple (use a length of 1" masking tape to mark out the hole position).
The upper edge sits flush with the edge of the dash but the bottom edge sits flush with the center console plastic rather than the dash.
I would also suggest using mild steel screws to fix then use a magnetic driver (same with all the screws behind the dash)
btw this is from an old picture before i sorted out the switch holes.