Networking is hard. There's a lot of stuff not easy for normal computer users. But, a simple as possible answer does exist and has for a long time :)
This isn't an OS thing to do. Its your wifi router, wifi AP, etc. that does this and that's where it has to be changed.
To do that, you access the interface for that hardware. Most home based routers for instance are used via the web browser. So you open up Edge, Chrome, Firefox, etc and type in the router IP address then log in to the interface. To find the IP address you have to look at your network connection stats and see what it is or look at the router manual (some might have it on the router sticker). Then you need to enter the default username and password if you've never changed it (also found in the manual or on the router), enter the changed ones if they were changed, or factory reset the router then enter the default ones.
In the browser interface, you then go to the wifi section for changing the wifi password, and change it. And done.
Someone else could walk you through it if they'd like to. But, here's a link that has images for some of it: https://www.pcmag.com/how-to/change-your-wi-fi-password You really don't need to do anything but search or read the manual. Again, its all been around for a long time so there's tons and tons of step-by-step guides.
You can't just change the password like you suggested as that is really bad for security, pranks, and everything ;)