adding fruit to a Riesling wine kit?

I have helped several friends with brewing of beer and wine, but am about to make my own for the first time. I was given a 'Selection Estate Series' Washington Columbia Valley Riesling juice kit, and a standard 6 gallon wine making equipment set. I generally like Rieslings, but sometimes find them a bit on the sour side. I'm a fan of ciders and slightly sweet, slightly tart wines. Would it be wise to attempt to add fruit or adjust this kit in any way? I was thinking pears or pear juice might be a neat twist. It was a pretty expensive kit, so I wouldn't want to ruin it, but I do like adding my own twist to things. Any one have any input on this for me?

I'd follow the recipe with the kit, at least the 1st time. After you make it that way, you'll be better able to judge just when, where & how to alter the recipe to your own liking. Regards, GF.

I would also recommend letting it finish as designed. After it's done, if it's too tart, you could sweeten it up some if you'd like. I wouldn't add fruit or juice- that would ferment and then it might be unbalanced and even more tart.