Can you tell me something more about your Estrella? How old is it and which model?
I know about the German Service Manual, but this is about a BJ250A (or B) from 1994. Not much things have changed until 1997, but it belongs to the type / model of Estrella you have.
The Service Manual (in German) is too big to be sent via email. I know someone in Thailand who has the German Service Manual on CD. If it makes sense with your Estrella, I might ask him to send you the CD.