As far as I know it must be uploaded back to the pool from the machine it was downloaded to.
You will need to log in as the other user to do that.
Otherwise you could contact your Archicad support people and ask them to return the license to the pool - but make sure you check if there will be any fees involved.
Or contact the remote employee and ask him to return the license.
You can always try the full version in demo mode.
One of the forum moderators.
Versions 6.5 to 25
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Dell Precision 3510 - i7 6820HQ @ 2.70GHz, 16GB RAM, AMD FirePro W5130M, Windows 10