My english is not too good, but maybe i can help you alittle.
First of all, you must download all the file first.
- twrp.tar
- twrp 3.2.3.zip
- gapps 9.0.zip (if needed)
- ROM xxx.zip
- last stable "magisk v20.4.zip" (if needed)
And copy all the files to your memory card.
Step :
1. Your phone must be grand 2 duos smg7102 & have the latest firmware updated.
2. Download twrp from this link
https://forum.xda-developers.com/galaxy-grand-2/development/twrp-galaxy-grand-2-sm-g7102-t3778414
- Flash the odin flashable.tar first (this only for whom never changing the stock recovery mode). And flash it via pc using odin software (youtube, how to flash ....). After done this flashing and then,
- Flash the twrp 3.2.3 (you must use this version to avoid some error). Just flash this version via recovery mode (youtube, how to boot into recovery mode grand 2).
3. And flash the ROM, flash it via twrp (youtube, how to ....)
4. Flash Gapps 9.0 (IF NEEDED), flash it via twrp.
5. For Rooting your phone (IF NEEDED). Flash magisk, latest stable version via twrp.
6. REBOOT your phone & DONE.
---------- Post added at 11:33 AM ---------- Previous post was at 11:10 AM ----------
Eh im forget some step.
After step 2 before go to step 3.
Or you can call it as step 3
3. Wipe all your data, wipe it from twrp. You can give check mark to all wipedalvik/cache, data, internal, system, etc. BUT DONT GIVE CHECK MARK FOR YOUR MEMORY CARD.
This step will erase everything, so do backup first before wipe all. Just in chase.
4. And flash the ROM, flash it via ......................