How does someone spoof a IMEI number on a android device? I have read about rooting the phone and stuff like that but can i do it without rooting? Any advice would be appreciated. Right now i am leaning towards rooting the phone and then corrupting the EFS folder and making a backup of the EFS folder on another Android and restoring the target EFS folder from that backup if i am correct this should copy over the IMEI
Yes, you need root and without root, it's not possible
Xposed module XPrivacyLua is what I use. I have the pro version which IIRC is needed for spoofing. Non pro blocks access. There are many more such Xposed modules, you find in the repo. Play Store has also some apps that claims to do this but I have not tried them because they cannot be as effective as Xposed modules.
What you propose is a cumbersome, may (if you have identical devices) /may not work approach and not worth the effort