How to restore dirty building?

[Still-learning]

I have a question about this image;



As you can see the sandstone building is old and dirty.
What is the best way to clean up this building?

I did several attempts, but all of them gave me a unnatural or blurry building..

 

[alixman96]

Here is a tip try to lighten up the building as a whole (but not too much because it gets unrealistic very fast) then the parts where it gets darker than other parts like the bell thingy on top of the building or the bottom of the building you can use the cleanest part of the building and take colour samples from there and work your way out in the dirty parts and use blend mode to blend it then desaturated it and then bring up the curve from the curve adjustment

EDIT: here is my quick and dirty samples I allways like to give people samples when I give them tips

 

[ibclare]

I am not a fan of replace color, but I think it would work well here. I tried selecting just one or two dirty brick colors and made the hue lighter and slightly more yellow than the dark grey brown I had selected. Then I did a levels adjustment and it looked pretty good. Unlike Alix, I am not posting it. I'm short a few bricks, lol.

 

[sprucemagoo1]

It depends on what you class a clean is, considering it is sandstone, It will look un natural if it is too clean. After deleting the rest of the background you had missed, the only tool I used was the dodge tool. If you are not comfortable with the pen tool yet, if you put a stroke on the layer, it shows the background you miss using the eraser.

 

[Still-learning]

Everyone thanks for the tips and advice, I can re-try with new ideas now.