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Be aware that rooting your device will prevent it for receive further security updates provided by Xiaomi. Also some apps may be able to detect that your device is rooted and will refuse to work (common are banking apps that only want to run on an unrooted device). So effectively the best way to get rid of the per-installed spyware is to switch the phone.
Although Robert probably has the correct long-term solution, the only other thing I would throw out here is that Android has the ability to disable most pre-installed apps... If these apps have that option, you could disable them.