Speedo sensor retaining pin
 

I've tried shit loads of WD, heat, breaking the sensor clip to free up more of the pin but my mole grips cant grip enough

Its stuck fast, any ideas?

I cant even snap it to be able to drill it

its one time you do need some decent grips

plus gas is a much better penetrating oil ...so maybe try that

then maybe some better grips , these knipex cobra dont slip

Speedo sensor retaining pin
 

Yes a good set of mole grips that clamp hard. Get yourself a can of wurth rost off ice, give it a good squirt and then it should start moving! Done a couple of these and you won't get it out without gripping it properly.