
Hello and welcome to the forum!
I think this has been covered in an earlier thread and from what I remember you have touch the lower set button and case at the same time - a fork is good to use for this, a slightly moist finger makes a better contact than a dry one!
I will dig out the thread and post it here!
Found it.......This ones a Macys but I think it's identical?
http://www.dwf.nu/viewtopic.php?t=1242&highlight=