I do not know where on the plant to cut. Only the head of the flower? The whole stem?
Where Do I Cut When I Remove Dead Geraniums?
Certified GKH Gardening Expert
You just pinch them off. This article will explain about it:
like most other flowers, deadhead at the flower only. cut no more than about an inch from the top of the dead flower. however, if pruning, the stem should be cut to encourage fresh, healthy new growth.
P.S i love geraniums! happy gardening!