To manage your licenses navigate to
https://<IP Address>:8090/serverstatus/litespeedStatus you will see something like:
If you click on License Status, it will only display your currently license and its expiration status.
You need to have your new license key in hand, before you use this option. This will open a box where you can enter your new key. Once you change your key you can again click License Status to see if your key is changed and new expiration date is reflected.