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Yeah, I'm with Federico - 100 doesn't seem like a ton, unless your total link profile is very small. I'm not clear on what you're trying to accomplish with changing the category in WordPress - is it the category page that's a problem? If the links are all to one page and you can live without that page, you could let it 404. If it's a category page, then yes, I guess you could change the URL. Just don't 301-redirect the old URL to the new one, in this case, because you'd carry the links and any penalty. If this was something like Penguin, you'd still have to wait for a data refresh. If it's a manual penalty, you'd need reconsideration. So, even total removal may not instantly fix the situation.