I've never had to ever modify a brand name part to make it fit.

But I found the answer to my question!

N62B48, and i guess N62B44 etc only have one fan, like Clavurion said!

So, I was trying to fix a second fan, on top of the first fan that goes inside the radiator (closer to the engine)

This is for M54 engines, for 3.0l, where there is a clutch fan, and an extra AC fan. On N62 engines, there's only one electric fan, and no clutch fan. That's it. So I was trying to add an extra fan where no fan js needed lol. Why parts catalogue shows it compatible with N62 is strange, since it's clearly not!

This also explains why there are no few replies. Because no one replaced the AC fan on their N62 engines, because it doesn't exist!