Complex sentence: Freytag-Loringhoven's cousin Wessel, who provided the detonator charge and explosives for the assassination attempt against Hitler on July 20 1944, was a friend of Freytag-Loringhoven but did not involve him in the plot.
Split into simpler sentences: Freytag-Loringhoven's cousin, Wessel von Freytag-Loringhoven, provided the detonator charge and explosives for the assassination attempt against Hitler. He was a friend of Freytag-Loringhoven but did not involve him in the plot.