Redmine

I have hundreds of issues (like 200) that need to be recategorized (a couple fields, specifically the category and one custom field need to be changed for every issue).

It's a manual process, but should take only 1 second per item. Unfortunately, the web interface to Redmine adds another 5 second delay, making it a really tedious process.

I was thinking to just open the Redmine database and make the changes directly in the table (obviously, very straightforward, since I know all the IDs of the new field values).

Is there anything I should be aware of? Can I just change the values for categories and custom fields, or might it create some other problems?

Thanks!