À bit of a faff, this will also help the engine to start better.
There are spill pipes between each injector but be careful as the last one closest to the windscreen has a blanking cap on it!
If it has become cracked as well, you get a small section of the same pipe and put a small bolt in it to seal the system.
There is also a section that comes from the fuel pump on the engine upto the first most accessible injector.
Replace that as well.
There are a couple of sizes for the inner diameter so maybe take a piece of the original piping with you so they can identify it's inner diameter. I'm not sure if its 3.2mm but don't quote me on that please.
They are all linked together in a chain like fashion. So the last injector is linked to the previous one in a forward direction towards the front of the engine and then onto the fuel pump.