Hall Sensor guide???

[PetDMC]

i read Lmandrake's guide but i'm still in the dark

i'd like to know how to mod it so a LED will light up when the magnet stops moving i all so want to have the RPM monitoring too (i don't want the fan blades moving= manual power/other source)

could anyone give me a more detailed guide?

Pics, lotz a pics

thanks