Complex sentence: With this equipment, the Germans managed to completely resupply their force and von Lettow-Vorbeck abandoned and destroyed the majority of his force's German weaponry for which he had no ammunition, and instead armed his troops with the newly acquired Portuguese and British materiel.
Split into simpler sentences: With this equipment, the Germans managed to completely resupply their force. Von Lettow-Vorbeck abandoned and destroyed the majority of his force's German weaponry for which he had no ammunition, and armed his troops with the newly acquired Portuguese and British materiel.