The possibility to downgrade from iOS 2 depends on whether Apple is still signing the older iOS version you want to downgrade to. Generally, Apple stops signing old iOS versions shortly after new versions are released, which prevents downgrading to those earlier versions. The downgrade process usually involves using a computer with iTunes or Finder, backing up your current data, downloading the proper firmware (IPSW file), and restoring the device to that version. However, if Apple has stopped signing iOS 2 or any other version you want to revert to, you cannot downgrade to it anymore. Given that iOS 2 is an extremely old version, it is almost certain that Apple no longer signs it, making downgrade to iOS 2 essentially impossible on any modern devices. Downgrades are more feasible between recent versions of iOS while Apple still signs the older firmware. If the question was about a very recent iOS version like iOS 26 (or some modern version), you could attempt downgrade within the signing window with the typical method: computer restore using the IPSW file and iTunes/Finder. Otherwise, downgrading is blocked by Apple.