How bad is it? The picture would help.

That said you can use a grinding wheel to remove it just make sure to feather out the area or you can use concrete resurfaced.

Thank you. At the other house right now but will try to add picture to post before dinner.

75% of contractors can't match color and texture when making repairs so I recommend creating a design. You can buy topping mix especially for thin layering and colorant if desired. Clean old concrete,alow to dry,use strong tape to lay out a star,octagon,circle or design of choice,mist water on surface then apply topping and mist for 24 hours to slow drying rate. Above 80f,below 40f,wind and/or direct sun can ruin thin concrete so you might want to look for ideal weather. Needless to say the desighn is limited only by your skill and determination. I've done multi-color and texture.

Alternately you can lay tile over it.

Or set a planter box over it. Which is what I would do. Because in 50 years, those kids may want to come around and find their handprints and remember that long ago day when they 'helped' Dad pour the patio.

Sorry for the delay. Unpacking and working with 4 little kids is a bit chaotic!

Yup, perfect place for a long planter box.

Cup wheel on a grinder, but you'll have to do it all to get the now-exposed aggregate to match.

Well that’s kind of an in-your-face display, isn’t it? I wouldn’t care for it either.

Planter box on it. Or tile on top of it.