rename the file and change vnw to rar and extract

you can use other programs also to open a rar file

The RAR file type is a type of compressed file. The contents of the file can only be accessed by using a decompression program that reads RAR files such as WinRAR. When you open the RAR file with an applicable decompression program you will be given the opportunity to extract its contents similar to a ZIP file.

Install a package called rar using Synaptic Package Manager or using

$ sudo apt-get rar

Once the rar package is installed then use following command to

# rar e <compressed rar file>

this will extract the contents of rar file in the current directory.

You can't - rar is archive format, while mp3 is sound file format.

You probably want to unpack rar file, you can use WinRAR or 7zip for that.