How do you remove a lower crankshaft pulley bolt that has snapped on a Citroen relay?

To remove a snapped lower crankshaft pulley bolt on a Citroen Relay, first, you need to access the crankshaft pulley. Attempt to extract the broken bolt using a left-handed drill bit, which can help to unscrew the remaining piece. If that fails, you may need to use a bolt extraction tool or tap the area around the bolt to create a clean edge for extraction. Ensure to clean the threads thoroughly and consider using a thread repair kit if the threads are damaged.