HELP! How do you take an existing image of a circle and thin the brushstroke?

[Schole]

Is there a way to thin the brushstroke of an existing image (see circle below):

[Monika Gause]

So the brush is already outlined? And in which way should it be thinner?

You could try out the existing brushes, maybe it's one of them.

[Schole]

The circle is a picture/image not created in Illustrator - I need the line to be 1/2 the thickness without completely erasing the brushstroke

[Monika Gause]

You could try and cut in in half at the edges. Then scale both those halves. Or try and use the Bloat tool: make the radius larger than the object. Set the intensity very low. Then click

[キィィ─!!!]

I don't understand English well, so I'm sorry if you get a strange answer.

Do you want the image brush art to be a thin brush art?

My method is as follows.

Open the image in Photoshop.

Move to the center.

Rotate so that the joint is centered.

Increase canvas size.

Convert polar coordinates with a filter.

Make the path.

Bring it to Illustrator and make it a brush.
Adjust the line thickness.

If I am saying something strange, ignore it.

[meganchi]

If the stroke is outlined already, then you could try to use the offset path function and plug in a negative value to make it thinner. Another easy option is to add a white stroke to it.