Thank you for contacting us.
In order to achieve this you have to navigate to Administration ->Labels & Messages and then find the desired label. for your convenience I have recorded a short video.
If you need any further assistance, feel free to write back.
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items