BPM form mapped to drop down "none selected" workaround

So I started trying some stuff.

I saw this post in the forum:

Which gets me to a coding guide. I found on page 10 for calling BO’s from custom code. Here’s my BPM so far

I added the assembly that I think I need.

I added the using statement, but this is probably wrong.

Then I added the code, this is obviously wrong. The example from the help has a lot more, but I don’t know what any of it means, and it just says “add the necessary code”, and I can’t google that so I’m stuck…

I’m pretty sure that I am just past my coding ability with this one, but if someone has an easy fix I would love the help.