Removing headset (is nothing ever easy)

[lewisdmz]

I thought i'd tackle the nice easy job of finding out why one of my speakers isn't working, and typically, the bloody headunit won't budge.

Both removal keys lock into place and the right side starts to move but the left does not budge one iota. It must not be releasing the catch or something, but without being able to see in there it's impossible to see what's going on.

Frustrating is not the word, anyone got any tips? I've got two sets of removal keys and both have the same issue, also tried doubling them up on one side but still the same.