To change settings you have to be leader of that guild or vice-leader: Roy Son Abar Celu Arcorn Habe Sha Korona Dumbledore Lafina.
In character comment at Tibia.com add following code:
guildstats-29500
If you have made it, just choose your country and click 'Set', to confirm new settings
In character comment at Tibia.com add following code:
guildstats-29500
If you have made it, just choose your country and click 'Set', to confirm new settings