Disclaimer: I am not responsible for bricked devices, dead SD cards, etc!
Warning: I didn't test this procedure, I did backup the images from stock Chinese version before installing global version but I didn't flash it back. Please test at your own risks!
1. Make sure your bootloader is unlocked
2. Download the images provided in the link below
3. Boot your device to recovery (hold volume up and power until reboot)
4. Wipe data
5. Boot your device to bootloader (hold volume down and power until reboot)
6. Connect your device to PC (make sure you have installed fastboot on your PC)
7. From windows command prompt cd into the folder containing the images
8. Run the following commands to flash all images
When flashing super.img, if you get the message Invalid sparse file format at header magic, this is fine.
9. You should then be able to boot into system
Stock RMX3300 Chinese images: https://mega.nz/folder/Ilk2CBwb#VMlU6A8wcFJVU0twOD6vTA
All Stock RMX3300 Chinese images (slot B was the correct one when it was backed up): https://mega.nz/folder/d1dxEBTa#nzKU4KuhnDcHjK7MX_D2eA
Warning: I didn't test this procedure, I did backup the images from stock Chinese version before installing global version but I didn't flash it back. Please test at your own risks!
1. Make sure your bootloader is unlocked
2. Download the images provided in the link below
3. Boot your device to recovery (hold volume up and power until reboot)
4. Wipe data
5. Boot your device to bootloader (hold volume down and power until reboot)
6. Connect your device to PC (make sure you have installed fastboot on your PC)
7. From windows command prompt cd into the folder containing the images
8. Run the following commands to flash all images
Code:
fastboot flash boot boot.img
fastboot flash dtbo dtbo.img
fastboot flash engineering_cdt engineering_cdt.img
fastboot flash metadata metadata.img
fastboot flash oplusreserve2 oplusreserve2.img
fastboot flash recovery recovery.img
fastboot flash splash splash.img
fastboot flash super super.img
fastboot flash vbmeta_system vbmeta_system.img
fastboot flash vbmeta_vendor vbmeta_vendor.img
fastboot flash vendor_boot vendor_boot.img
fastboot --disable-verity --disable-verification flash vbmeta vbmeta.img
fastboot -w
When flashing super.img, if you get the message Invalid sparse file format at header magic, this is fine.
9. You should then be able to boot into system
Stock RMX3300 Chinese images: https://mega.nz/folder/Ilk2CBwb#VMlU6A8wcFJVU0twOD6vTA
All Stock RMX3300 Chinese images (slot B was the correct one when it was backed up): https://mega.nz/folder/d1dxEBTa#nzKU4KuhnDcHjK7MX_D2eA