One way trip

Today is my day off. So no flying, no problems........or...help out a friend.
We planned a round trip to Barth Intl Airport (Germany) today. Due to techinical problems with this single engined Piper-28 our planning had to change.
No mechanics at this airport. Maybe the ADAC knows how te fix the starter problem? Not having any tools with us every help could be usefull. Unfortunately the suprised mechanic (we didn't inform him that he was expected to fix the starter of an airplane) did his best but left without succes.
We aranged another airplane to bring us back home and left the Piper for repairs.