Consider the quote from Boney that I had already pointed out to you; I'll emphasize a few sections this time. You could, perhaps, argue that Old One monoliths are smaller than waystones, but I see no evidence for that. There isn't much talking about how big nexuses are, but the handful of descriptions imply that they are bigger. The idea that we can just airlift it out is an obvious nonstarter.It might be, or it might not - it really depends on how big this rock is. We know it's big, but it'd have to be pretty massive for multiple gyro carriages working together not to be able to lift it.
I don't think it would need deactivating though - this is the main part of a Nexus that was never turned on and got nicked, not one that was ever in use.
You are correct that there shouldn't be a connection to disconnect though.
moving a [waystone] that would weigh dozens of tons without damaging it even slightly when the cutting edge of transportation technology goes 'neigh' is likewise not the sort of job anyone would be rushing to volunteer for.
You spend some time staring at the towering stone maypole at the centre of the public green - 'the largest maypole in the Empire!', you remember being told when you spent a night in a tavern here - and smile.
....
You pass through Achaes, a town built on nothing in particular with its crude huts clustered around the base of the nexus like nervous chicks clinging to a mother hen