Someone created a record for a family member and accidentally marked this person deceased and we cannot seem to change it.
Select the "Death" record.
Select "Living"; and, add a "Reason Statement".
That "Reason Statement" should indicate as much details as possible that the individual/person is a Family member of yours; and, the fact they are STILL "Living".
That should "Create" a 'Support' Case; which, I think (but, do not quote me), IF, 'FamilySearch' agrees (with you); THEN, they should mark the individual/person as "Living"; and, as far as I am aware, 'all things equal', that individual/person should be "Transferred" to you and placed in your "Private Spaces", as a "Living" person; but, it can be complicated - See the information in the "Knowledge Article" below.
But, that is NOT immediate - the case has to be actioned - it may take a few Hours to the next day.
Here is a "Knowledge Articles" in 'FamilySearch':
How do I change the status from deceased to living in Family Tree?
I hope this helps.