Can't remove projects someone in my group shared with it

Hi,

I’m working with a small company, and a developer who just left has given some old code to us by importing it to his own namespace and sharing it with our group (on gitlab.com).

I’ve successfully forked and archived the projects into the actual group namespace as originally intended, but am now unable to remove the ones from his namespace (which are not editable) from the group’s projects list.

In despair, I’ve tried using the API:

curl -XDELETE 'https://gitlab.com/api/v4/projects/_project_/share/_group_' -v -H 'PRIVATE-TOKEN: __'

But I just get 403s, presumably as I’m not owner of the projects, just the group.

Is there any way at all I can get these things out of the list? Sadly the person responsible is going to be impossible to reach for the near future.

Thanks in advance for any help possible,
Tom