Do not change the file names (e.g., part1 , part2 ), as this breaks the automatic sequencing.
Ensure you have filename.part1.rar , filename.part2.rar , etc., in the same directory. Use 7-Zip or WinRAR: Right-click only on the Part 1 file. Pert 1 rar
Select "Extract Here" or "Extract to..." from the menu (e.g., in WinRAR, select "Extract to [folder name]"). Do not change the file names (e