BSP_tools support files folder has files and a readme to set up BSP_tools.
I advise you read it well so things work correctly.

dod_mainz tut VMF folder holds the files made while perfecting the method.

HL1 decompile tools has some popular HL 1 decompilers if you need them.
Some of those are hard to get.

Other tools mentioned will have a download link in the tutorial.

Enjoy

INsane.