Question [Q] P6 MIUI 3.12.22 to 4.8.18

Hello guys,

I got some questions regarding JB and KitKat.

I'm right now using Huawei P6-U06 wit Android 4.2.2 and MIUI-3.12.22 wich is JB and i would like to use Huawei P6-U06 KitKat MIUI V5 4.8.18 by Ry09iu wich is KitKat.
I want to know if I have to first flash back to Stock-ROM B125/B132 and then upgrade to B512 to get KitKat Android and so I can flash the KitKat MIUI 4.8.18 or can I just flash the KitKat MIUI 4.8.18 over my current MIUI 3.12.22 without getting problems?

Thanks in advance!