Tell me what you need to do next, and I can provide a step-by-step guide.
Searching the public internet for direct download links to "NSP" or "XCI" files poses significant security and legal risks. mario kart 8 deluxe switch nsp xci update 30 link
Update 30: What It Brought to the Table
If you are searching for a "link" to Ver. 3.0.0 or 3.0.5, the answer is simpler than you might think. You do not need to download a separate file. Your Nintendo Switch can do the work for you automatically. Tell me what you need to do next,