you'll have to unpick the stitches one at a time. There is a tool which my mum used to call a 'pick-un-pick' with a thin sharp pokey thing, or use a small pair of sharp scissors, to get the point under each stitch and snip. BUT you'll probably still be able to see where the pocket was, there'll be lots of little holes left from the stitches, I don't think it'll look great.
I put my sewing question in homes and gardens and it got lots of great suggestions. The most useful one was "ask your mum - she'll know just by looking at it" - and they were right! If this isn't an option for you shadow221, perhaps take it to work and ask someone who is a mum - they really do seem to know everything! :-)