I'll respectfully disagree. I've replaced the master cylinder on my oilhead with ABS. I completely drained the system, replaced it and filled it up again. I use a mityvac: handheld. It worked fine as it has on my TDI VW, my Montero and every other vehicle I've owned over the last 10+ years.
Now the oilhead did take some tapping here and there, cracking the banjo bolt at the master cylinder, but with patience and feel, it was back to normal inside of an hour.
Please keep in mind that I'm not disagreeing that you had trouble. I've never done a K75. I'm disagreeing that every vehicle with ABS is difficult.
If a mechanic at the BMW shop can do it, so can you. The difference is, you need a reference to refer to....like the BMW Repair CD Manual or some other reliable reference.
There is NO MAGIC to maintaining and repairing these motorcycles we ride...mere mortal man can fix it......so can you!