I concur with those advocating the use of a vacuum. Make some type of reducer for the hose and attach a length of SMALL rubber automotive vacuum hose. You may be able to have some room to maneuver the small hose around and possibly convince the plastic piece to come out. A dab of grease on the end of the hose may improve your chances. Good luck!

I’ve taken the head off of my ‘95 E300 twice. I’ve not experienced any leaks as a result.