Anyone who practices thaumaturgy or theurgy knows how to whip up some shiz (with varying degrees of skill and thus success no doubt) and there are plenty of guides to this sort of activity that have been concocted over the centuries. But not so many folks offer tips on how to undue work that may address issues successfully resolved or that, the mage may have thought better of having addressed. The Witch of Lupine Hollow addresses this vacuum in this blog post.
https://witchoflupinehollow.wordpress.com/2017/01/19/how-to-dismantle-an-old-spell/