Hi,
This can be done in several ways.
All settings can be changed via the CLI/SSH client. The LAN interface settings can be set in the /etc/config/network directory. Note that if you change the LAN name, you need to check if it has changed in other configurations, such as Firewall.
Alternatively, you can create a new LAN interface via Web Ui Network> Interfaces page, and then delete the existing one.
Best regards.