If you wish to update your concurrent license, then you can just to run the CostOS Server installer (right click and click Run as administrator)
then click on the first option (I accept the agreement) and then click on the Next button.
Verify that your installation path is correct and leave the first option (Yes, update the existing installation). Then click on the Next button.
Now, click on the Concurrent License.
Tick on the box (Use concurrent license mode) and upload your .lic file. Click on the Browse button to find your license file.
Find your file e.g server.lic and just click on Open button.
Click on the Next button and finally click on the Finish button.