To access Webalizer for addon domain without loging in to the Cpanel can be done by following the steps
1. Login to the server using SSH
2. Then change directory to the Document Root of the addon domain
cd /home/username/public_html/AddondomainFolder
3. In the desired folder create a symbolic link
ln -s /home/username/tmp/webalizer/addondomain.maindomain.com webstats
4. Change the permission of the folder
chmod 755 /home/username/tmp/webalizer/addondomain.maindomain.com
Now you can access the stats using http://adondomain.com/webstats