Definitely disconnect the battery! Vlad is right just get a 10mm spanner I think it is and disconnect the negative terminal (black). Just to be on the safe side I always do with any engine work it stops any dash lights popping up afterwards. And make sure the MAF sensor is plugged back in before turning the engine on. I rushed putting it all back together and forgot to plug it back in, my CEL came on and I had to use a diagnostic tool to turn them off. Hope this helps!
That's what she 'Zed' :-/