Although there are several ways to install this set of plugins, the following is what we recommend...
1) Make a new directory under your current plugins directory called "Brazil". Place the four plugins "braziltestrend.dlr", "braziltestFX.dlv", "brazilcore.dlu", and "braziltestmtl.dlt" into this directory.
2) Now the ini file. Edit your plugin.ini (located in your root max directory), and add your brazil directory to the list. An example is below.
Standard MAX plug-ins=D:\3dsmax\StdPlugs\
Standard MAX plug-ins=D:\3dsmax\Plugins\
Save this ini file as Brazil.ini.
3) Now copy your current shortcut to max to make a second shortcut to max. Righclick it and choose properties. Go to the shortcut tab, and make sure you're using the brazil plugin ini by typing the following...
D:\3dsmax\3dsmax.exe -p brazil.ini
in target (replacing d:\3dsmax with whatever your max install is).
4) Now if you run your original shortcut, you'll get a copy of max with all your original plugins. Running this new shortcut (which you may wish to name "Max Brazil") will load max with the new brazil stuff.
5) The Brazil Render is a Renderer plugin now. In max 3, go to Customize, Preferences, Rendering, Current Renderer, Assign and choose Brazil. In R4, go to Rendering, render, go to the "current renderer" rollout and assign the Brazil Renderer.
6) Brazil now works with watever materials you have in your scene - no need to convert everything to the Brazil test material. Have "fun".