破損したsudoを修正する方法 - sudo：ライン5の近く/etc/sudoers.d/ADSMの解析エラー？

$ sudo
sudo: >>> /etc/sudoers.d/ADSM: Alias `TSMADM' already defined near line 5 <<<
sudo: >>> /etc/sudoers.d/ADSM: Alias `TSMCMD' already defined near    line 18 <<<
sudo: >>> /etc/sudoers.d/QUALY: Alias `TRSC' already defined near line 1 <<<
sudo: >>> /etc/sudoers.d/QUALY: Alias `TRSCOPERATION' already defined near line 3 <<<
sudo: >>> /etc/sudoers.d/RCCM: Alias `TCAINST' already defined near line 17 <<<
sudo: >>> /etc/sudoers.d/RCCM: Alias `TCAUNINST' already defined near line 20 <<<
sudo: >>> /etc/sudoers.d/RCCM: Alias `TADDM' already defined near line 23 <<<
sudo: >>> /etc/sudoers.d/RCCM: Alias `TAD4D' already defined near line 24 <<<
sudo: >>> /etc/sudoers.d/RCCM: Alias `RCCM' already defined near line 24 <<<
sudo: >>> /etc/sudoers.d/TOP: Alias `NORSUDO' already defined near line 4 <<<
sudo: >>> /etc/sudoers.d/TOP: Alias `NOVISUDO' already defined near line 4 <<<
sudo: parse error in /etc/sudoers.d/ADSM near line 5
sudo: no valid sudoers sources found, quitting
sudo: unable to initialize policy plugin

sudoersファイルを編集するためにルートディレクトリに入る方法を教えてください。