Yeah that's right. You remove the comment in the .inc file and recompile.
To recompile you go to the examples folder and doubleclick the compile.bat file and it recompiles all the .sma files in the examples folder and puts the compiled files in the "compiled" folder inside the "examples" folder. Then you select all the files inside the "compiled" folder and copy them to the plugins folder, replacing all existing files.
That's it. All done
BTW the reason you should always download the .sma files when you download a plugin, is because the plugin needs to be compiled with the .inc files inside the "examples/include" folder of the exact version of AMXmod you are using for full compatibility, and you should recompile the plugins that come with the .zip file of AMXmod anyway, so it's really a must to know how to compile in AMXmod.
MusicMan