Brake fluid flush question

[1olddude]

I have a Motive power bleeder and read all the threads and articles on flushing the brake fluid. I am going to attempt my first flush and feel pretty confident in my abilities but I have one question. Should I use a turkey baster to remove as much of the old fluid from the reservoir before I begin with new or do you just pour the new in with the old and bleed it all through until new fluid comes out at the calipers? I haven't seen this addressed in any of the articles I have read. It seems strange to just mix the new fluid with the old. Any tips would be appreciated.