First, did you know that the man pages are available online here at Method R? They are also available wherever you have the tools installed. Just use the --man argument to any of the tools. For example:

$ mrls --man | more

But you did ask about actually installing them, so, assuming you're on a Mac or Linux system, then it's done this way.

First, you need to decide where to put them. The man program uses MANPATH to determine where to find your man pages. To find your current MANPATH, execute this:

$ man --path

/opt/local/share/man:/usr/local/PDK/share/man:/usr/share/man:/usr/local/git/share/man:/usr/X11/man

If you find a "local" path you like, you can just add our pages there. If not, you may want to add a directory to that path. The components to MANPATH are found in /etc/man.config on Linux or /private/etc/man.conf on Mac.

Once you have decided on a place, copy the files mr*.1 to the man1 subdirectory of that path. For example, here's a command I executed:

$ sudo cp mrls.1 /opt/local/share/man/man1/

The files are usually compressed with gzip, but this step is optional.

$ sudo gzip /opt/local/share/man/man1/mrls.1

I now get the man page correctly when I need it:

$ man mrls