If you use only 4 users. Then reduce the number in assigned cals field.
Count the number of cals assigned to all document
check filed No. of Cals allocated to this document.
If 2 users using document if this field have 4.
Then you need to downgrade it to 2.
by this your cal will be released.
Hope that helped
I think you need to remove assigned cals. In the same tab.
There might be some users whoom you have authorized before.
But now you don't want them. For this reason I suggest to remove assigned users to Document.
It the Unwanted user dosen't log in for the last 24 hours cal can be released immediately.
If not it will take 24 hours of time to remove that particular user.
Note:- Care have to be taken that the user you wana remove should not be logged in for 24 hours.
From the time you removed it. Or else the counter will be reset from the last logon time till 24 hours.
Hope that helps