To change the permissions of a file, perform the following steps:
Select the file that you want to change.
Choose File ▸ Properties. The properties window for the item is displayed.
Click on the Permissions tab.
To change the file's group, choose from the groups the user belongs to in the drop-down selector.
For each of the owner, the group, and all other users, choose from these permissions for the file:
No access to the file is possible. (You can't set this for the owner.)
The users can open a file to see its contents, but not make any changes.
Normal access to a file is possible: it can be opened and saved.
To allow a file to be run as a program, select Execute
To change the permissions of a folder, perform the following steps:
Select the folder that you want to change.
Choose File ▸ Properties. The properties window for the item is displayed.
Click on the Permissions tab.
To change the folder's group, choose from the groups the user belongs to in the drop-down selector.
For each of the owner, the group, and all other users, choose from these folder access permissions:
No access to the folder is possible. (You can't set this for the owner.)
The users can see the items in the folder, but not open any of them.
Items in the folder can be opened and modified, provided their own permissions allow it.
The user can create new files and delete files in the folder, in addition to being able to access existing files.
To set permissions for all the items contained in a folder, set the File Access and Execute properties and click on Apply permissions to enclosed files.