76 MB 240D [115]: I've removed the injectors and replaced the nozzles but I can't get the heat-shield washer out of 1 of the chambers. I've applied WD40, 'Liquid Wrench', diesel fuel, and biodiesel in an attempt to lubricate the chamber; I've tried prying the washer out with several instruments [which worked with 1 of the others that was also stuck], but I've only succeeded in mangling the washer itself, which remains stuck to the bottom.
Any ideas about cleaning agents to use or other techniques to try?