Cleary you're not understanding me, if you've changed your IP before it means you have a dynamic IP, what you do is obtain your routers IP (type in your router brand and model on google) and search for the IP, once you've obtainedthe IP copy the IP into the search bar and click search and now a login screen should pop up asking for your username and password, your username is most likely Admin and your password is the password you use to connect to your WiFi, once logged in go the Mac Address tab and I believe it's clone Mac Address once in there you'll see you have I believe it's 4-5 rectangles with letters from A-F combined with numbers from 1-9, go to the last rectangle and change it with any letter between A-F and change the number with any number between 1-9, once finished click save settings and restart your router and bang there you go you now have a new IP