There are a few different ways to reimage an Android tablet, depending on the make and model of the device. One way is to use a software tool like Android-x86 to create a bootable USB drive or SD card with the new operating system image. Another way is to use the fastboot tool to flash the new image directly to the device.
If you are not sure how to reimage your specific device, you can consult the manufacturer's website or support forums for more information.