kogyaru

Greetings. I've got a one-eyed 1989 GL-10 wagon and I'm trying to replace the halogen bulb on the bad headlight. The bulb is secured to the back of the assembly with a yellow plastic locking ring. Whoever fastened it last (before I got the car a decade ago) over-tightened it, and I'll be danged if I can't remove it without breaking something. Might someone have an idea of what type of tool would be best for loosening this plastic collar? Adjustable pliers aren't big enough to go around the collar and would strip the teeth on its exterior. Tried using my belt but that didn't work. It's on too tight.