Windows 10 'N' version - how to add back the missing media package?

A friend's computer is running W10 Pro, not sure of the exact build but it's about two years old.
He's been having issues with playing videos. Turns out it's an 'N' version of W10, which I understand was created for the European market, ie, it's short on some media features. Apparently it can be patched with a certain Windows Update file, namely 'Microsoft-Windows-MediaFeaturePack-OOB-Package_x64.msu, so I've downloaded it.
Only problem is, this guy (and his wife) are absolutely terrified that the patching process might screw their system in some way.
It doesn't seem likely to me, but I'd like to know for sure if I'll run across any fishhooks before I attempt the operation.
Anyone familiar with this process?
PS: Windows Updates is switched off and he doesn't want it re-enabled, so I'll just be unpacking and running the .msu file.

Looks like it should be installable as an optional feature. https://support.microsoft.com/en-us/...d-e378f82f252c

The same instructions apply for more recent versions of Windows 10 (and 11).

bobkn: Thanks but although the mentioned 'Add Features' button is there, it doesn't work. Seems I'll need to install the .msu file.