you click the remove brown stain button under the remove red stain button!!!!!

Try this...

Invert the colors with [CTRL]+[i]
Pick up the color of the stain while inverted
Revert to normal colors with [CTRL]+[z]
Set your paintbrush at a very low opacity, like 2-3%
Go over the stain area with the inverted color you just chose.
It will slowly neutralize the stain.

the stain looks bad, but i can see the photo under it nicely. the clone stamp isnt good enough for this. can anyone help? or give me a tutorial?

The Clone Stamp tool and choose a sample area of ​​the image. Then these pixels can be used on other brands of paint. It is also useful in the replication of objects and covers defects in an image. To put it simply, copy exactly what area is being presented in the picture.

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