Hi Mary
You take the local train from Munstertal to Staufen - this is a 9 minute trip - buy ticket locally
Check schedules for Staufen to Florence at:
https://reiseauskunft.bahn.de/bin/query2.exe/en?protocol=https:&rt=1&
EDIT: the 9:48 train has only 3 changes and arrives in Florence at 18:59
Here is one of the trains:
Staufen 07:48 10:11 hrs travel time 4 train changes SWE, ICE, IR, EC, ES
Firenze S.M.N.** 17:59**
Station/Stop Time Platform Products Further information
Staufen dep 07:48 SWE74330 Südwestdeutsche Verkehrs-AG Direction: Freiburg(Breisgau) Hbf
Number of bicycles conveyed limited , 2nd class only , Einstiegshilfe durch Zugpersonal im 1. Fahrzeug. Anm.: 07821/9960770
Freiburg(Breisgau) Hbf arr 08:14 3
Transfer time 47 min.
Freiburg(Breisgau) Hbf dep 09:01 3 ICE 5 Intercity-Express Direction: Basel SBB
Bordrestaurant
Basel SBB arr 09:47 12
Transfer time 17 min.
Basel SBB dep 10:04 7 IR 2319 Interregio Direction: Locarno Number of bicycles conveyed limited , Reservation optional , Observation coach
Bellinzona arr 13:51 3
Transfer time 5 min.
Bellinzona dep 13:56 2 EC 17 Eurocity Direction: Milano Centrale
Subject to compulsory reservation (Chiasso --> Milano Centrale), Global price (Chiasso --> Milano Centrale), Bordrestaurant (Bellinzona --> Como S. Giovanni), Bordrestaurant (Como S. Giovanni --> Milano Centrale)
Milano Centrale arr 15:35
Transfer time 45 min.
Milano Centrale dep 16:20 ES 9545 EuroStar Italia Direction: Napoli Centrale
Subject to compulsory reservation , Global price (Milano Centrale --> Bologna Centrale), Bordrestaurant , space for wheelchairs
Firenze S.M.N. arr 17:59