www.boxertrix.com

Boy was I pissed off when this happened to me on the first time I fuelled up my new bike.
Because those black bits are painted you can remove the white splash stains by carefully wiping them with a cloth dampened with paint thinners.
What your doing is taking off a bit of the paint with the stain ...

I found a copy of the manual after a brief search of the net. Is in pdf format and runs to some 26meg.It is the original bmw manual of 1999 so no four valve, and seems quite easy to follow.
Here is a page from the man

showing that the manual has both pictures and line drawings.
Hope that works ...