In this picture the part in the blue circle, what do I have to do to replace this part, it leaks from the connecter part to the fuel rail. Thanks

Quick disconnect for the fuel lines. You don't need to replace the fitting, just the O-ring that goes inside it. Parts counter at your local dealer, or measure it and check the small parts aisle at the local auto parts store.

am i able to replace the connectors? if i am where can i buy them

The actual connector is molded into the fuel line and isn't replaceable by itself. You need the entire fuel line down to where it joins the steel lines that run under the car (driver side frame rail, down under the brake booster.) That kinda sucks, but there it is. Really, check the O-ring inside the quick disconnect first. There'* a second style as well that has the O-ring really burried inside the fitting and it can't be replaced except by replacing the entire line.

I dislike this arrangement and replace the quick disconnect fitting with AN flair fittings to -6 hose.