Edit title ID with extracted NCCH header and ExHeader

This mini guide explains how to change the title ID (specifically unique ID) in an extracted NCCH header and Extended Header (ExHeader).

Examples in this guide use information for USA Super Smash Bros. for Nintendo 3DS (00040000000EDF00).

Note this might break Download Play, unless the CIA inside the Download Play child container is edited too. A guide for this will be worked on eventually.

Requirements

• An extracted NCCH header and ExHeader
  See Extract .cia on details for extracting. Use 3dstool to extract the NCCH header, or manually save the first 0x200 bytes of the contents.
• A hex editor
  Any should be fine. Suggested ones:
  • Windows: HxD
  • Mac: Hex Fiend
  • Linux: Bless (your package manager might have it)

Each unique ID is three bytes long and stored in little-endian, so the bytes are in reverse order. For example:

• EDF is 000EDF normally,
• 00 0E DF when separated by bytes, and
• DF 0E 00 in little-endian.

Editing NCCH header

1. Open the NCCH header (might be ncchheader.bin), or CFA in your hex editor.
2. Find the unique ID in two locations:

• 0x109
• 0x119

3. Edit the two locations with your new unique ID.

Editing ExHeader (only for CXI)

1. Open the ExHeader (exheader.bin) in your hex editor.
2. Find the unique ID in three possible locations:

• 0x1C9
• 0x201
• 0x601

3. If the unique ID is at one of these locations, edit it with your new unique ID.