Motherboard replacement ACER connector pins don't match

Hello

Last week I made a post about an Acer M3641 desktop. It came to the conclusion that the motherboard had to be replaced. The new motherboard is a G31M-GS R2.0 ASRock with a 775 socket.

The case is still the one from the Acer. I connected all the cables and pins, but there is one major problem! The pins that are responsible for the leds, powerbuttons and reset contain 13 pins with 1 dummy.
However the ASRock motherboard has a standard one, which contains only 10 places for the pins.
I wonder if there is a solution for this? How to solve this?
I’m afraid of taking all the little cables out and reputting them, since that’s nervewrecking and tiny work :-).
I also put 3 pictures. Two of them are the coloured cables with the pins, the other one is the location where it should be placed on the motherboard.

I’d thought that I might cut out some pins, and maybe let the cables from the leds out, but I don’t know which colour is what. I could easily cut out the power button cable. And nowhere on the old motherboard or on the cables itself is written which function they have…
So any suggestions are welcome!

Thanks in advance!

Kind regards
Maxx-iT