Turn Ikea Expedit shelf & desk around

Hello
I have the Ikea Expedit shelf with 2x4 compartments and the desk in an "L" shape.

Now I want to turn the shelf around. (so that it is 2 boxes high and 4 wide.)
And the desk should stay attached as well.
However, this doesn't work because the thing for fastening only goes 2 cm apart and I need at least 5.

Does anyone have an idea how I could do this? Or does anyone have experience themselves?

It is best to make two new things for fastening or have it done in a small locksmith's shop. That is probably not that expensive at all.