That is the fuel pressure regulator......can be done by a DIY'er.....
Relieve fuel pressure....remove fuel pump relay or fuse and crank the vehicle...car will start and die.....place rag under the reg to catch what drips out....
Where the fuel line comes out of the bottom, there is large nut...must be backed off, and the line removed.....then to the left is a torx bolt, that hold a retainer on the reg.......remove that....then pull the f/p reg out of the rail....should be an o-ring on the reg...if not, it is inside the rail....be sure to remove it.....use petroleum jelly on the new o-rings to make installation easier......
If you need the fuel line to have more play for assembly/disassembly, follow it to a clip that holds the supply and return lines together...remove the clip(bolt), and you'll have more "play"....good luck...
Remember, you are dealing with fuel here.....wear protective glasses, and don't do this on a hot engine...