Hi anyone using the Studio Projects VTB1-RK ?

I'have just purchased 2 x VTB1 Mic Preamp and 1 rack kit.

Can someone explain me how to mount them on their rack kit?
I am forcing so much to take out the VTB1 side screws and they
don't come out!
:x
And what's the use of the 2 metal pieces that come with the rack kit?
I can't find any information to mount them.

Please help me out!

Thanks!

PS- I am talking about the Studio Projects VTB1-RK (Rack Kit), that they
made to be able to screw 2 units on it, not any rack shelf...