You don't actually "open" part .003 directly. Instead: Navigate to your folder containing all the parts. Right-click on Part 001 ( Bedplay.7z.001 ). Select 7-Zip > Extract Here (or "Extract to Bedplay/").
Download and install the 7-Zip Official Tool or WinRAR. Bedplay.7z.003
To create a blog post centered around a file like Bedplay.7z.003 , which is typically a multi-part compressed archive, you should focus on providing clear instructions on how to handle it. You don't actually "open" part