You can do this by using the customize. On Customize go to-> Basic Settings->Your Copyright Name, And all details there.
In Addition, we noticed that you need copyright symbol ahead of year and only one All Right Reserved Text. So, you need to edit the footer.php. on footer.php line no:33 you can get the code.
and replace the code with the following
Sorry, I’m a little confused. You mention going to Basic Settings->Your Copyright Name. I already have “Andreas Ian Jahn” there (the copyright holder). I don’t see any more “details” there. Just a place for the name.
Your next suggestion… Are you saying I REPLACE the top section on line 33 with the single line you suggested? Where is the “All rights reserved” and where is the copyright symbol? Am I missing something?