I've heard that a Perditio pickaxe can break one (and only one) spawner, if you hammer on it for about ten minutes.
There's also various ways to move spawners using other mods, including MFR's Portaspawner.
On the other hand, you can open up .minecraft/config/GregTech/GregTech.cfg and change the "B:harderSpawners=true" line to "B:harderSpawners=false". This will make the spawners behave as in Vanilla.