Trouble activating 2024, can't change serial number.

I'm trying to activate Solidworks 2024 student. It installed fine but I forgot to activate and the trial expired. I have a serial number I purchased from Solidworks but for some reason it won't activate over the internet. I tried the manual email route; I emailed the file to activation@solidworks.com and the response I got was to change the serial number. I don't know how to change the serial number when I can no longer open the software. Can someone help me?

Edu