Thats tough to fix - i tried it and its so overexposed on the light it is hard to fix.
Try opening the raw (if you have it) in photoshop with exposure turned way down and then blending (click move tool, shift they drag on top of the one with good exposure and then reduce the opacity. This might help. I am not sure.
If you reshoot, use AEB and 2 stop difference and then you have an exposure that you can blend for a better fixing of light.
I tried to copy a bit of the image (from the left bit of the photo) over the spot - fiddle with the skew and curves etc to try to match it to the rest of the photo
very rough - but better than the spot - nice photo
I thought about doing a crop, but it didn't look right to me, so I was going to keep the bottom portion. With it cropped like that, it won't print nicely without even further cropping, right?
I'm trying to figure out where you were to take this? A long lens from the convention center, or the hotel?
I'm not a photoshop guru, but in my experience bright spots like the one in the lower left are very hard to get rid of. There is no data in those pixels to massage. Burn it and the light spot becomes a dark spot, cloning with all that detail and not drawing attention to the clone will be hard. Having said that beebibi's clone is very good.
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