I tried to edit the question "Do: Experience with the journal" to be of a more a question and answer format, following some of the other changes I've seen on the site. I changed the question to "How does the Journal in Do: Pilgrims of the Flying Temple affect play of the game?" but I couldn't submit it, because I didn't make an appropriate number of changes to the body of the question, i.e "Edits must be at least 6 characters; is there something else to improve in this post?". The edit was more than 6 characters; they just happened to fall in the title. Is this really not an acceptable edit?
The edit requirement of 6 characters is only on edits to the question body. As such, if you want to modify the title, but don't have at least 6 characters of changes to the question body, simply make sure you make 0 changes to the question body.
Same goes for tags, by the way - those can be done without any restriction. The only issue is touching the body - essentially, it blocks edits of 1-5 characters. If your edit is 0 characters then you're in the clear.