Clean up these stairs?

[Splitting_Atoms]

Im working on a picture for a client...and they are asking me to clean up these stairs and remove some of the sand/white stains on it.

I can clone this away, but there must be a better way. I was thinking using a 'darker' layer and use 'blend if'...but im not sure how to do this (whatshould I use to blend with)... and Im not even sure this is the best way to do this..

Can anybody edit this for me? It doesnt have to be perfect..I just need to make the stairs a little bit better...here is the image

 

[chrisdesign]

 

[Babine]

 

[Splitting_Atoms]

Oh crap, I posted this in the wrong section haha. Thank you so much @Babine and @chrisdesign , but I just wanted to know how you would approach this in Photoshop. I didnt mean for you guys to actually do it. But now I see i posted this in the free photoshop request section.

My apologies. Can somebody still tell me how to do what you guys did?

thanks !

 

[Dormeur74]

I began but...
The method I intend to use : Prepare a perfect stair (A) and duplicate it.

 

[Babine]

Oh crap, I posted this in the wrong section haha. Thank you so much @Babine and @chrisdesign , but I just wanted to know how you would approach this in Photoshop. I didnt mean for you guys to actually do it. But now I see i posted this in the free photoshop request section.

My apologies. Can somebody still tell me how to do what you guys did?

thanks !

I made a selection both the dark stairs and the light dividing fill (Select/Colour Range) to alpha channels; filled both with sampled colour using these channels; spot healing brush to blend those stains that were still visible; select curves adjustments for contrast with the mask to blend in.