If the archive is encrypted, the password is usually found on the original forum post or site where you found the link.

Right-click on part1.rar and select "Extract Here." Modern tools like WinRAR or 7-Zip will automatically detect the remaining parts (including Part 3) and stitch them together into a single file or folder.

You must have every single part (Part 1, Part 2, Part 3, etc.) in the same folder before you start.

Files found via search terms like "download-noire-part3-rar" can sometimes be hosted on sites that bundle malware.

If Part 3 specifically shows an error, try redownloading only that part. Most extraction tools will tell you exactly which part is failing. Provide more details so I can give you more precise help.