good advice - of course try to grip an end of the cable somewhere, failing that there may be a wire pull visible from one of the wheel liners, ie a cable threaded through wing where some electrical wires are. If you don't have the luck with either, the only other way is to drill a hole directly underneath the catch, use a coat hanger wire to pull it open etc. Most specialists know where to drill to do that, most folks who try end up with many holes and still don't hit the right spot. The wire pull is on the nearside I seem to recall. You need to take off the front wheel, remove the wheel liner and hope to see a cable end coming thought through a wiring grommet.
Good luck.