Manage ACL

We are in the process of upgrading our R5 server .

i had installed a test Domino 8.5 server ,in this i am not getting the option of managing ACLs . earlier in R5 i could give rights to any user to another users database by manage the ACL, this feature was very useful . i want to use this feature can any one guide how to do this easily… editing INI file looks risky to me

Now when i try to edit any file using admin id im getting a message as "Warning This server is not configured to support Directory ACLs. This feature can be enabled by setting ENABLE_ACL_FILES=1 in the servers NOTES.INI "