Removing the power to reboot can be tricky and could risk dropping the phone base or damaging the power connector or the network connector (in the case of PoE power).
Rebooting a Yealink W52P/W60P phone base without this is a simple proceedure using the "user" account in the web interface. Note that this method should work with all Yealink phones:
If the reason for your reboot is related to difficulty in updating your configuration, you might be recommended to Factory Reset your phone.
Yealink W52P / W52H