The short answer is yes, you can.
The more complicated answer is, be careful. While the radio button on the Settings > Permalinks page is easy to use, when you change your permalinks, all of your old links break.
They go to a 404 error page. This means all of your traffic will see an error and you won't get traffic anymore.
This is why a redirect is necessary if you plan on changing your permalinks.
We'd be happy to do this for you if you want to change them. Please just contact us in this widget or email at firstname.lastname@example.org