Click on the firmware details on the right panel and hit . Save the files to a dedicated folder on your computer. Step 2: Create or Prepare the .FTF File

If your SO-01J still boots but has issues:

: FTF (Flash Tool Format) or extracted package via XperiaFirm Essential Prerequisites

A full stock firmware flash will completely wipe your internal storage. Back up your photos, contacts, and messages to a cloud service or an external microSD card.

For advanced users, here is a practical summary based on community findings.