Manual Installation:

Choose 1
EITHER
Gale's Wizardly Updo_Default - Replacer
OR
Gale's Wizardly Updo_Longer - Replacer
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Drop the "Generated" folder(found within your chosen file) in your "Data" folder within your BG3 root directory.

\SteamLibrary\steamapps\common\Baldurs Gate 3\Data


So it should end up this looking like this:
\SteamLibrary\steamapps\common\Baldurs Gate 3\Data\Generated\Public\Shared\Assets\Characters\_Models\_Hair\Resources\HAIR_HUM_M_Gale.GR2