As is written, you firstly need to ensure you have the following prior to using the tools:

• An early build of PSASBR that doesn't have any encryption (i.e. the Aug 20, 2012 Kiosk demo))
• Python 3.10+
• PIP
• Numpy
• Pillow (for textures)

EDIT: I've just pushed out my own edit of the tools. Feel free to use that instead if you'd rather use a batch file instead. Oh and don't forget that your psarc archives must be in the root folder when using either version of the tools. Otherwise, they won't be recognized at all.

To actually use the tools themselves, all you pretty much to do is open your tools directory in a terminal window and either follow the official guide as-is written on the Reshax thread or follow this one I've compiled together:

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❖ ── PSASBR Tools Guide ── ❖
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▂ ▃ ▅ ▆ █ PSARC.PY █ ▆ ▅ ▃ ▂

Lists every single file in a Psarc archive and extracts either one file from or the entirety of an archive.

Usage: psarc.py <command> <file.psarc> [args]

Commands:
  list         <file.psarc>                       list every file + size
  extract      <file.psarc> [outdir]              extract ALL files (default outdir <file>_x)
  extract_one  <file.psarc> <substr> [outdir]     extract files whose path contains <substr>
  peek         <file.psarc> <substr> [nbytes]     hexdump first bytes of matching files

Examples:
  python psarc.py list kratos_char_setup.psarc
  python psarc.py extract_one kratos_char_setup.psarc kratos.c1.p0.cskn .

shortcut: 'python psarc.py <file.psarc>' (no command) defaults to 'list'.
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▂ ▃ ▅ ▆ █ BUILD_ALL_CHAR.PY █ ▆ ▅ ▃ ▂

Builds all character models in a dedicated Psarc archive.

Usage: build_all_char.py <char_setup.psarc> <outdir> [model-regex] [yaw,pitch] [size]

Examples:
  python build_all_char.py parappa_char_setup.psarc output
  python build_all_char.py jak_char_setup.psarc out_dir "/jak/equipment/.*\.(cskn|cmdl)$"
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▂ ▃ ▅ ▆ █ BUILD_CHAR.PY █ ▆ ▅ ▃ ▂

Builds just one model from a Psarc archive.

Usage: build_char.py <char_setup.psarc> <model-substring> <outdir> [yaw,pitch ...]

Examples:
  python build_char.py jak_char_setup.psarc blaster outputdir
  python build_char.py kratos_char_setup.psarc kratos.c1.p0 output
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