Any files shared here in the forum are uploaded to a third party site and from there users download them. It's strictly up to how the originator of the file chooses to release the file as to whether or not it's design elements are accessbile or not. That said, every file I've shared and most files I've seen shared are fully accessible--though some shared by others came with a password that may have been sent out via a private message to prevent others from opening the file--but usually this means you can't even open the file without that password.
I'd take a look at how you've downloaded the file if you can't use Manage | database to open and examine how it is designed or can't use Manage | scripts to see how the scripts were written. Files downloaded in a compressed archive such as a zip folder cannot be modified until you decompress them. Many default download locations for a web browser are automatically 'read only' locations and you have to move the file out of that folder before you can open and investigate the design of the file. You can also check the file's properties to make sure it is not set to "read only".