Change the owner


I have to change who can modify some layouts. I thought that changing the owner of these layouts would work. But apparently, it doesn’t. The new owner can see the layouts, can chose to modify them, but once you reach the regions level, you discover you can’t change the timeline inside. But I have checked that no specific permission was settled for the region (even the name of the previous owner) : it meant to me that an owner can do everything.
Is it necessary to give permission to each regions in each layout ? It would be so time consuming :confused:
Or if so, can I just modify the account of the former owner and give it a new name, change the password ? Would it work ?
Thanks !