Undo chown/chmod /usr/bin

[chepkasov]

Hello, guys, I did a huge mistake, wanted to change chown for /usr/local/bin and changed for /usr/bin... :-(
Now I can't use "sudo" and others...
Tried to change it back and operation is not permitted.
Help me to solve it please, or tell me, should I reinstall Mac OS?
And if is possible to do:
1. Make a backup with Time Machine
2. Reinstall Mac OS
3. Restore with Time Machine

Thank you in advance!

 

[chepkasov]

[SOLVED] If somebody have this problem just enter the Recovery mode (Cmd+R on start system), use terminal, go to your Volume, and use this chown root /usr/bin/sudo && chmod 4755 /usr/bin/sudo