Soonich, the answer to your question is yes.
Even if your US driver's license expires here, they'll accept.

And for the other question as to the sequence.
1. get the form (can get it from the transportation office at Uetlibergstrasse and i was told some optician has it as well)
2. then go to an optician/optometrist to get your eye check and they'll fill in the neccessary section for you)
3. then bring your driver's license, attach a passport sized picture and submit to the office.
4. if your license does not fall under the list of countries where automatic conversion is permitted, you'll be given a date to do your driving test, which is a case for me.

hope this helps.