SMALL TUTORIAL FOR VENDOR / COUNTRY CHANGE [DEMO REMOVE] ON HUAWEI P20 / P20 Pro
1. Make the TP so that the 'HUAWEI USB 1.0' port gets visible
(can get the drivers from https://drive.google.com/uc?authuser=0&id=1klEAYQovLVSzyRv1AA4iBq6cuC1u1AOL&export=download)
2. Go Update OEMINFO tab
3. Mark 'Use bootloader' and select Kirin970_Tx_Vx and press update (x here marks the fact that you must try all the available Kirin970 loaders until you find the one that matches your device)
4. Once the proper bootloader is found (means boot written and phone goes in fastboot mode) reconnect the phone with TP so that the 'HUAWEI USB 1.0' port gets visible
5. Now mark 'Update OEMINFO' as well and select EML-L oeminfo file
6. Set 'hw' for the vendor and 'normal' for the country and 'EML-L29' / 'EML-L09' for the 'model' (no quotes for the values)
7. Press Update
8. Once this process ends put the phone in upgrade mode ( vol up + down and insert usb while keeping the volume keys pressed)
9. Go 'Update firmware' tab and select update_EML-L29_184.108.40.206(SP5C900)_hw_normal.cfs if the model is 'EML-L29' or update_EML-L09_220.127.116.11(SP5C900)_hw_normal.cfs if the model is 'EML-L09'
10. Press 'Update'
11. If all made properly then you have a fully converted demo phone now
NOTE: For P20 pro at step 8 you must write both firmwware and the customisation