Advanced users may strip out specific setup bundles to speed up deployment on test devices.

A utility to convert Apple's compressed DMG files into mountable images.

The best source for downloading original firmware files.

Before starting, ensure you have a "decrypted" IPSW. Most modern iOS versions are encrypted, requiring specific "keys" to view the contents of the DMG files. 1. Extract the Contents

Modifying a firmware file is usually done for one of three reasons:

An IPSW (iPhone Software) file is a single compressed archive that contains the entire iOS or iPadOS operating system. Apple uses these files to deliver updates and restore devices via Finder or iTunes. Internally, an IPSW is essentially a renamed ZIP file containing:

Will reject modified IPSWs because the digital signature no longer matches the original.

Use a tool like TransMac or HFSExplorer.Now you can browse the iOS file system. You can add apps to /Applications , modify system strings in .plist files, or change boot logos. 4. Re-encrypt and Pack