yeah this step is kinda annoying but its really easy
im using debian systems (ubuntu and kali 2) so it was easy
edit the ~/.bashrc , i used nano so it was " nano ~/.bashrc " in terminal and i just scroll down to the bottom and add both lines
export WECHALLUSER="BigSnipes" --> example for ur login
export WECHALLTOKEN="FAKE-TOKEN-ASDA" --> your token
and yes it has to have the quotes
and for the other file " nano ~/.ssh/config" in my case the file didnt even exist , so i just created it and added the following content
Host *.labs.overthewire.org
SendEnv WECHALLTOKEN
SendEnv WECHALLUSER
finally just connect to the level you are on overthewire and just type wechall and it should say something about score updated

if it does show an error just post it here