No, the springs don't get cut. Actually, the Racetech springs for the f4i and 919 forks are the same. They will come with spacer material (aluminum tubing I think). You'll need to get some measurements, then cut the spacers such that the springs are compressed ~15mm (with preload backed completely out) when the forks are assembled. There are more detailed instructions that come with the springs, and there are threads available on this subject as well that give the finer details.
Edit: I think there is a range of acceptable preload. I just threw 15mm out there based on other suggestions made on this forum.
'96 DR650, '01 SV650, '10 Aprilia Tuono 1000R