Converting XCI to NSP is a simple and convenient process, but questions about how to do this appear almost every day. Therefore, I decided to provide instructions to dot the i and forever. The program that we need is called 4NXCI.
From source Only 4nxci_GUI
! There should be no Cyrillic alphabet in the path to all files (only Latin characters and numbers)!
2 In the XCI field, select the source file of the game in the XCI format.
3 In the Output Directory, specify where to save the resulting NSP file (by default, this is the program folder).
4 Keyset File you should load automatically. If not, in this field specify the location to the keys.dat file (in the distribution in the root of the folder).
5 Click the Convert button.