I created a document which is now ready for printing. I realized, that I made it to big. A few millimeters. So I created a slice in the export personna and some guide lines, to cut off 2 millimeters on each side. Now, slices do not snap to my guide lines, and I just cannot position it properly.
If there is an other way to cut my document by 2 millimeters on each side, let me know. I just need to export it as pdf for printing.