This solution was posted in the cPanel forums at: http://forums.cpanel.net/showthread.php?t=9713. In addition, this article is a modified version of http://www.andrefaca.com/2007/10/06/webalizer-showing-another-language-instead-of-english-heres-why/

Webalizer is compiled with cPanel and sometimes, non-native english speakers like me forget about this and will use a non-english user to run Webalizer for the first time. Webalizer will be compiled with the language that the user has set to be the default. It can be Spanish, Portuguese even Russian.

To make English the default language for Webalizer, do the following:

1. Backup your original webalizer binary and language files by running the following commands on a root shell:
   
   • mv /usr/local/cpanel/3rdparty/bin/webalizer /usr/local/cpanel/3rdparty/bin/webalizer.backup
   • mv /usr/local/cpanel/3rdparty/bin/english/webalizer /usr/local/cpanel/3rdparty/bin/english/webalizer.backup
2. Get the english binary and language files:
   
   • cd /usr/local/cpanel/3rdparty/bin/
   • wget http://www.andrefaca.com/non-deletable-files/andrefaca.com/files/webalizer-binary.zip
   • unzip webalizer-binary.zip
   • chmod 0755 webalizer
   • cd /usr/local/cpanel/3rdparty/bin/english
   • wget http://www.andrefaca.com/non-deletable-files/andrefaca.com/files/webalizer-english.zip
   • unzip webalizer-english.zip
   • chmod 0755 webalizer
3. Now, run webalizer:
   
   • /scripts/runlogsnow

Note:
You should allow the runlogsnow script a few hours to run, depending on how many domains you have. If you want to just test it out on an account, you can instead use the command:

• /scripts/runweblogs USERNAME

Webalizer is now in english!