My friend gave me a video in real media video, but the right channel of audio has very low volume. Is it possible to demux the audio file out of the rm file to fix it? If this is possible, what would I use to do it? That would be my preferred solution. But if I have to jump through a lot of hoops to fix this, I am willing to do it. Thanks.

Grab yourself a copy of Matrix Mixer and use Media Player Classic to play your files. You can adjust per-channel gains by right clicking the video and choosing filters-MatrixMixer-Gains.

Apparently I am unable to access the filters menu when playing the rm files I have (in media player classic). But for my other files (avi, etc) the filters menu is available and the matrix mixer is easily accessed. Are real video files special or am I just doing something wrong?

Get yourself newest version of the Directshow RealMedia splitter from http://sourceforge.net/projects/guliverkli and disable Mpc's internal rm-splitter.