How to install the downloaded maps:

Copy all the files with the extension .bsp to your maps directory
Copy all the files with the extension .txt to your maps directory
Copy all the files with the extension .wad to your tfc  directory
Copy all the files with the extension .wav to your sound  directory

Example directory structure

Half-Life\TFC --->	        --- *.wad
		dlls
		logs
		manual
		maps		--- *.bsp, *.txt
		media
		save
		sound		--- *.wav		
		tfstats
             