It was important to understand that this seal is not all rubber. It's 2 concentric rings of of metal surrounded by rubber. I found it best to use something like a dental pick, with the tip shaped like a fish hook. Push this into the seal, between the gap of the 2 cocentric metal rings, and hook on to the outer ring and pull. Maybe a crochet needle would work too. Just be careful not to scratch any camshaft surfaces with it.