If you want to access French only content from outside the country then you'll need to use a proxy or VPN server. Many of the major media sites, forums and video sites restrict access based on your location. They determine this by looking up your IP address when you first visit the site.
There's nothing you can do to change this IP address as it's assigned by either your ISP or the network you connect to, these will always be linked to the specific country you are in. Although there are a few instances where addresses are mistakenly registered - i.e. recorded as being in the wrong country.
Mostly though you will have to hide your real address and use one from the specific country you need. This is done using an intermediary server such as a proxy or VPN, which can be in any country you need.
So for example if you use a proxy or VPN that is based in France, then you can effectively change your IP address to a French one. This video demonstrates the process using a piece of security software which also allows you to encrypt your connection if needed.