Hi Mercedes Guy:
I have a 300E, not a 190, but the first time I changed the bulbs, the plastic lock collar on each light was jammed shut. I think road dust and humidity had glued things shut. I spent several minutes on each bulb twisting and rocking, blowing them out with an 'air' can of computer dust cleaner trying to get them loose. On mine I seem to recall there was a rubber seal that the collar seated against which had also glued things together.
Maybe one of those rubber strap wrenches like they have at Sears would help - just make sure to not turn the wrong direction, or too far, as 10 year old plastic is probably starting to get brittle. I wouldn't use oil or WD40, however, as petroleum lubes might weaken the plastic. I have never tried it, but perhaps a couple drops of baby oil around the collar/headlight interface an hour or so in advance of your next removal attempt?
Good luck - I am sure some 190 owners will have more appropriate advice.
2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)
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