Help replacing my headlight bulb?

I'm trying to replace the headlight bulb in my 2000 Honda Accord. I can't unplug the wire harness to get to the bulb. I'm pressing down on the tab and pulling/pushing down at the same time. I just can't get it to come off. Is there some kind if trick to get it off or something?

Do not know your exact situation but there are similarities in most cars.
The wires direct on the bulbs should not be too difficult, using the blunt end of a screwdriver pushing up and off with one motion then turn the bulb counter clock wise about a quarter turn and put, outback in in reverse except you want to avoid touch the new bulb the oil from your fingers is apt to burn it out after a little use.
If you are talking or of there's a main plug in or if you actually need to get it apart to change the bulbs. That one could have a red piece of plastic in it that needs pried out to the side then push and pull the plug in, or may be that it needs pried up instead of pushing down then apart. A closer inspection can tell.
There's the basics, good luck

Sorry, I don't know what to say. It's as simple as all that. I've never had trouble changing one.