If a value is denied if the approval workflow, it can't be changed.
You can however, the workflow obsolete. Click "Arbetsflöden för godkännande" or the corresponding text in you language of choice.
Here we see our value that we are unhappy with, and it's corresponding workflow:
Right click and mark this workflow obsolete:
You have to have permissions according to the reference manual: http://www.redbex.com/referencemanual/obsolete_approval_workflows.html
The value goes back to ready, we can now mark it as "Ange som pågår" or you corresponding text.
When we have done this we have to close and open the feature.
After we have done that we can edit the observation and restart the approval workflow.