Hi Dieter, it's good to see you in the REC Zone !
The advice that Alex and Cosmin have given is really the only way to do it so I won't repeat it again. You're in the stage of still concentrating on where your fingers need to go so you're not quite ready to let go of things and feel the groove just yet.
Once your fingers are able to move to where they need to go without requiring hard thought, you'll be able to concentrate on the timing then. I'd suggest keeping this track as an ongoing project where you can take your time with it and improve it section by section. In the meantime I would look at some easier lessons to help you accomplish your immediate requirements which is timing and changing chords/picking notes.