Bithumb verification for foreigners - How is it actually done?

Hi,
I'm from Germany and would like to have my Bithumb account verified. It seems like there are very few people outside Korea who have actually done it and they don't give any valuable information on how to do it. The Bithumb website doesn't give to much information as well.

I'm especially confused with the details of the documents one has to send to Bithumb.
What parts of my Passport should be covered?
Are there any limits or special requirements for the uploaded file? Bittrex for example has a limit of 8GB and 8000 squarepixels for the uploaded documents.

How long does the verification process take? I've read from different sources that sometimes Bithumb doesn't respond at all.

Can anyone here please help me out with my questions?

Thanks in advance