How to clean a white rubber watch?

I just bought a white rubber neff daily watch from zumiez and it says to take to the protective plastic off of the bracelet part. But it doesn't want to come off. I've been trying to peel it off for over an hour but only got a liitle off. What can I do to try to clean all this stuff off? Also, in the future when it gets dirty, how should I clean it? What do they mean by a "mild detergent"? Thanks