You don't need to mod any of your stuff.
The following works for Windoze XP.
Download FoxBotv697.zip (it contains FoxBotv697.exe).
Download it anywhere, unzip it and run the executable FoxBotv697.exe. The executable is an installation program, not the foxbot application itself. If you answer the questions right, or it correctly finds your HalfLife folder, it'll create a FoxBot folder and load everything into it or subfolders.
Then download FoxBotv698-upg.zip which contains (only) foxbot.dll. Unzip and move foxbot.dll to the ..HalfLife/FoxBot folder which should now exist.
The FoxBot folder should contain the dll, some htmls and a "tfc" folder which has areas, waypoints, etc., to support the default tfc maps (2fort, rock2, etc.).
You shouldn't need anything else. Just the command line "hl.exe -dev -console -game tfc" should do it. You don't need the -dev -console but it's always handy.
From the TFC 1.5 start menu, select Multiplayer/Lan Game/Create Game, select a bsp, click Ok. You'll spawn and, after maybe 20-30 seconds, a screen splash for FoxBots.net fades in and out and bots start to spawn. FoxBots should automatically spawn 7 bots to fill in the (usually) 8 players default, 3 more on your chosen team and 4 for the other team.
I'd like to hear whether you get foxbots running or not.
Nice detailed post, thanks - Seventh