Hello,
I’m looking for a fic where Xander helps free Spike from the chip. I think they’d become allies and Xander then uses a something from a construction site (maybe an electromagnetic kinda thing?) to disable the chip to free Spike. I think it was a risk in terms of would it work/how safe it was, but they succeeded. I read it years ago and would love to reread, hope it sounds familiar to someone.
Found it! It's 'My Scorpion':
https://spanderfiles.com/arvs/firehorse/ms.html