If the official method doesn't work or isn't available, you can use a third-party patch. Here's a reliable source:
: These are large .iwd files (e.g., localized_english_iw00.iwd ) that contain the English voiceovers and cinematic audio. Step-by-Step Installation Guide
In the main directory, delete files named localization.txt , localization_mp.txt , and localization_zm.txt . : Extract your downloaded English pack. Move the new english folder into the zone directory.