Not to be overly pedantic, but you will need to remove the intake runners to get the fuel rail out, and then you can remove the injectors. The hex heads take a 5mm wrench. A fairly long ball end hex wrench will make your life better, particularly one that fits a 3/8" ratchet. As you remove each runner, put a rag in the intake port to prevent anything falling in and causing you a bad day.
There are metal clips that connect the injectors to the fuel rail. These are easily removed with a pair of needle nose pliers (and easily dropped into the valley between the heads, where you must fish them out with a small magnet wand).
The AMP connectors that connect the wires to the injectors are often brittle and will crack or possibly fall apart. They are available aftermarket, reasonably inexpensive (at least in the US). Installing is a bit of a fiddle.
As mentioned by others, you'll want new o-rings top and bottom. The injectors are common Bosch form factor used on many brands of car, the o-rings are equally common and widely available.