Hello Willedue
Considering your post is old I still thought that I would give you a good tip -
Gemeinschaftszentren GZ Bachwiesen Holzwerkstatt has a complete set of bike tools and the shop director Christoph is very friendly and willing to give a hand if you first don't succeed yourself. I'm up there quite often myself.
http://www.gz-zh.ch/oeffnungszeiten/index.php?gz=3