Huawei P9 Plus User Manual page 20

By default, backup data is saved to the HuaweiBackup folder in Files.
Restoring data from a microSD card
1
Insert the microSD card containing the backup files into your new phone. For more information
on inserting microSD cards, see
2
Open Backup.
3
Touch Restore >
4
Select the backup you want to restore.
If the backup data is encrypted, enter the encryption password when prompted.
5
Select the data you want to restore, and then touch Start restoration.
Inserting a SIM card and microSD
Restore from SD card > Next.
Transferring Data
card.
13