Hi milan.ziga,
I would recommend you to begin looking at the new Unified Self-Service (USS) capabilities and plan towards using this for the business users/consumers and if this isn't an option right now then think about using Open Space with your existing versions as an alternative front-end to the business users. (The SDM end-user interface isn't really business user friendly...)
However, to answer your specific question, I would normally assume that any re-categorization of incidents would be done by the SDM analysts, not by an end-user. What's the use case behind your ask for end-users to change the category?
John