Sbsp-bfbfr-nswtch-[base]-nsp-ziperto.part1.rar

Ensure you have all parts (part1, part2, etc.) in the same folder before you start the extraction of part1.

For files from that specific source, the password is almost always: Quick Tips for Extraction: Case Sensitivity: Make sure to type it in all lowercase. SBSP-BFBFR-NSwTcH-[BASE]-NSP-Ziperto.part1.rar

Use a modern extraction tool like 7-Zip or WinRAR to avoid "Header Corrupt" errors. Ensure you have all parts (part1, part2, etc