Hi
There is something wrong in your SOAP message. You must use <deviceName uuid = "Value"/>, it is not device of phone
Please try this. This is only the SOAP message, you need to set Authorization (User, Password), SOAPAction.
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns="http://www.cisco.com/AXL/API/8.0">
<soapenv:Header/>
<soapenv:Body>
<ns:doDeviceReset sequence="1">
<deviceName uuid="' + APhoneUuid + '"/>
<isHardReset>false</isHardReset>
</ns:doDeviceReset>
</soapenv:Body>
</soapenv:Envelope>
It worked for me. APhoneUuid is uuid of device (ex: {008F29C4-7CC8-2D7E-245B-394E3D16106A})
Regards,