I need some help with M535i front

I hope you can read some English. My German is to bad to write here unfortunately.

I've got this problem: I have an European E28 525i from jan. 1986.

Now I've bought a M535i front and I want to put it on, but it won't fit. The problem is that the iron part behind the bumper doesn't fit.

Does anyone know:

1. Do I have to remove the iron which is behind the original bumper?
2. The airducts for cooling the brakes hit the iron when I fit the bumper/spoiler. Is the iron front that different between M535i and a non-M535i?

Which parts do I have to remove or replace to fit the M535i bumper?

Hope you can help me. Answer can be normally in German, I can read Germen pretty well, I just can't wright it that well.

MFG. Pepijn

Mein Holländischer E28 fanpage