If you log in to your ISP's machine from your home machine, you have two options. If you have the right permissions, you can run analog on your ISP's machine. Otherwise, you can download (e.g., ftp) the logfiles from their machine to yours, and then run analog on your machine.
Once you've downloaded the right version of analog for your computer from the analog home page (or a mirror site), you need to know how to set it up and run it. This is very easy, but the instructions are slightly different depending which platform you're using.