Just use a metal pin and a bolt with threads matching the hole to pull that rotor.
BMW tries to sell that crap for way more than it's worth too.
When I bought my charging kit for my r90, it came with a small metal dowel and a standard bolt. All it does is push that dowel against the bottom of the hole while the bolt threads into the rotor and pushes against the dowel to pop the rotor off the cone of the crank.
If you're broke, think like a broke man
I know I always do!