help me make this tiny

Ok, so my friend needs to make his own avatar for this forum, and he's got a picture of dr. weird from ATHF he wants to use. so he took opened the pic in photoshop and cropped out dr. weird's head and hairarium, and it looked fine, problem is it's gotta be 100X100 pixels max and it's also gotta be a max of 6kb. He can't get the image to be under 6kb, and still be 100X100 pixels. We've tried everything resizing and resolution changing and adjusting and things, and still can't get the image size down to under 6kb. so the question is, what can he do to the image, to just make the size small enough to fit the requirement, but preferably keep the size around 100X100 pixels?

Has he tried going into PS and using the "Save For Web" gif selection? I find that often crops off enough size when it's close.

make it the size you want it to be, then press ctrl + shift + alt + s (Save for Web). Click on the arrow to reveal options and choose optimize to file size. You just input the file size you need it to be and it optimizes it to it for you automatically.

That only took a few seconds. 4.5k.

Is this what you wanted?:

Damn that was a waste of my 4.5 seconds MechDeus.

Someone else do it too.

Thanks a lot guys, he'll be very pleased. And he wrote that post up there, in the third person. That amuses me.