Front door... removing oddment tray holder tool

Latest thing to stop working is the speaker on front passenger side. 

Was going to take the door card off this evening to see if I can spot the problem (loose wire/dodgy connection).

ive taken a rear door card off before, so have some idea, however, I cannot get the oddments tray holder out, even with following the rather rubbish instructions in my Haynes manual.

can anyone point me in the direction of where to buy one of the tools to get the clip on the tray undone, or what diy method I can shove in the hole to release the clip to get the tray off. (Tried a screwdriver, which hasn't worked).