If you prefer a pre-printed replacement, various retailers on eBay sell reproduction box art inserts specifically for original Xbox games. Complete Sets (CIB)
For on the original Xbox, finding the original "paper" components—specifically the instruction manual and cover art—is common for collectors looking to complete their "CIB" (Complete In Box) sets. Manuals & Documentation SSX 3 [Xbox Classic]
If you are looking for digital versions to view or print, or original physical copies to buy: If you prefer a pre-printed replacement, various retailers
You can often find sellers offering the SSX 3 Instruction Manual Only on eBay for around $4.99–$7.74 if you already own the disc and case. If you prefer a pre-printed replacement