Update or Uninstall

[CSNLinux]

Today I wanted to try a new appearance for XFCE Desktop.
Downloaded it through:

Code:

sudo add-apt-repository ppa:nikount/orta-desktop

after installing updating was advised but that didn't work

Code:

csnlinux[member=7334]CSNLinux[/member]:~$  sudo apt-get update
[sudo] password for csnlinux:
Hit:1 http://ppa.launchpad.net/atareao/atareao/ubuntu xenial InRelease
Hit:2 http://ppa.launchpad.net/nemh/systemback/ubuntu xenial InRelease         
Ign:3 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial InRelease   
Hit:4 http://ppa.launchpad.net/nilarimogard/webupd8/ubuntu xenial InRelease   
Hit:5 http://ppa.launchpad.net/otto-kesselgulasch/gimp/ubuntu xenial InRelease
Hit:6 http://repo.linuxliteos.com/linuxlite citrine InRelease                 
Hit:7 http://ppa.launchpad.net/ubuntu-wine/ppa/ubuntu xenial InRelease         
Ign:8 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial Release     
Ign:9 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main i386 Packages
Ign:10 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main all Packages
Ign:11 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main Translation-en_US
Ign:12 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main Translation-en
Ign:9 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main i386 Packages
Ign:10 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main all Packages
Ign:11 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main Translation-en_US
Ign:12 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main Translation-en
Ign:9 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main i386 Packages
Ign:10 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main all Packages
Ign:11 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main Translation-en_US
Ign:12 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main Translation-en
Ign:9 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main i386 Packages
Ign:10 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main all Packages
Ign:11 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main Translation-en_US
Ign:12 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main Translation-en
Ign:9 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main i386 Packages
Ign:10 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main all Packages
Ign:11 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main Translation-en_US
Ign:12 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main Translation-en
Err:9 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main i386 Packages
  404  Not Found
Ign:10 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main all Packages
Ign:11 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main Translation-en_US
Ign:12 http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial/main Translation-en
Hit:13 http://mirror.transip.net/ubuntu/ubuntu xenial InRelease               
Hit:14 http://mirror.transip.net/ubuntu/ubuntu xenial-security InRelease       
Get:15 http://mirror.transip.net/ubuntu/ubuntu xenial-updates InRelease [102 kB]
Hit:16 http://mirror.transip.net/ubuntu/ubuntu xenial-backports InRelease     
Hit:17 http://archive.canonical.com xenial InRelease
Fetched 102 kB in 7s (14.3 kB/s)                                               
Reading package lists... Done
W: The repository 'http://ppa.launchpad.net/nikount/orta-desktop/ubuntu xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: Failed to fetch http://ppa.launchpad.net/nikount/orta-desktop/ubuntu/dists/xenial/main/binary-i386/Packages  404  Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.

So is there a way to get the updates, otherwise what is the right command to un-install this package?