You can download the patch selector here.
When you've received the package, extract it to the root of your Enemy Territory directory. This means for most of us: C:\Program Files\Wolfenstein - Enemy Territory.

You now have 6 files:

- ET.exe.260 (ET.exe version 2.60)
- ETDED.exe.260 (ETDED.exe version 2.60)
- ET.exe.260b (ET.exe version 2.60b)
- ETDED.exe.260b (ETDED.exe version 2.60b)
- sleep.exe (Delay tool for the patch sequence, which is useful for ASE)
- patch.exe (The patching tool, to copy and rename the files above)

Summary

  1. Downloading the package
  2. How it works (manually)
  3. How it works (The All-Seeing Eye)