Wine Brewing Question

I have been homebrewing beer for several years and consider myself an intermediate brewer, but this is my first time 'brewing' wine.

I was given one of those box kits (Heron Bay Shiraz) as a gift last Christmas but I haven't made it yet. It's been sitting in the box, sealed, at room temperature for almost a year now. Is it still good to make? I've tried calling the company but haven't gotten a response yet.

I called my local homebrew shop and they said it's probably ok, but that I should buy new yeast for it. Should I also replace the following ingredients, or are they still good after a year (room temperature, in the box, sealed in plastic or paper packets):

-Sorbate
-Kieselsol
-Bentonite
-Metabisulphite
-Chitosan

Thanks,
chris.

Only the yeast needs replacing, the other things listed are inert and have long shelf-lives.