Right-click on and select "Extract Here" using a tool like WinRAR or 7-Zip . The software will automatically pull data from part03 and all other segments.
Because large games are often too big for a single download, they are broken into smaller numbered parts (part01, part02, etc.). You need in the same folder to successfully extract the game. What you need to know about this file: Gears.of.War.4.part03.rar
Ensure you have downloaded every part of the set (e.g., part01 through partXX). Place all files in a single folder. Right-click on and select "Extract Here" using a