Default [Q] Restoring sms.db

Cant find the answer here or on Google .. so posting in the hope somebody can help!!

Huawei G300 needed to be Factory Reset ... followed the system instructions by allowing the device to create a Backup.zip file containing a number of *.db files and an *.xml file under the directory /mnt/ext_sdc/HuaweiBackup ... which is all fine .. but HOW does one go about restoring this data after having performed the Factory Reset????

I have searched google to the limits ... no advice unless i had used a third party Backup and Restore APP in the first place ... so it seems!!

All i need is to restore the SMS.DB file ... can somebody suggest how or point me to where i might find the solution???

Many thanks in advance