Travel from Bolzano Italy to Murren or Interlaken

I've done this trip multiple times both via car and train (almost, but heading towards Zurich rather than Berner Oberland). The drive is about 5-6 hours and will take you through the heart of the alps. The best route is via Meran, Zernez, Davos and Landquart,but you can also go over the Brenner through Austria (equally scenic but the Brenner can have horrendous traffic jams). Via train you can go either via Innsbruck/Zurich or Milan/Brig. It'll take you a little longer but the scenery is nice on either route. For schedules on that check out sbb.ch Driving is easy (there's a rental pickup at the Bozen airport), but there will be a nice drop off charge if you choose to dropoff in Switzerland. If your plans include returning to anywhere in Italy it might be better to keep the car and return it in Italy.