Delicate operation,
But if you don’t Format /data, there could be a chance.
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Would be safer if someone can test the procedure
(I have no access to a computer this weeks)
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You must use a Samsung OTA update firmware (only 1 file firmware, also called “Home_CSC” firmware), that will let the “Home” untouched (called /data in android)
DO NOT use a Samsung full install firmware (generally 4 files, also called “CSC” firmware) that will erase the “/USERDATA” partition.
Simply put the “one file firmware” in AP