How to retrieve multi select option set field from crm using C#?

Hello all!

How do I retrieve multi select option set field from crm using C#?

I tried this but it doesn't seem to work and it's a bit too advanced to me to debug.

http://www.itaintboring.com/dynamics-crm/dynamics-365-v9-multi-select-option-sets-c-and-sdk-versioning/

Can anyone show me how it's done?

Thank you!