Correct.
So, if you do cancel, the ticket will go to the inactive tab on:
https://www.united.com/web/en-US/app...n/default.aspx
When you want to make use of the SEK 4016, you'll go here and click "Change Flight" and effectively make a new booking.
At this point, you'll pay the SEK 1200 fee.
If the new booking is less than SEK 4016, you'll get a refund by way of an e-Cert for the difference.
For what it's worth, SEK 1200 is about GBP 98, which to me, is very good for a K class change fee.