Uninstall times out - help!

Hi,
I'm trying to uninstall via the product manager but it times out.
I have tried it lots of times.
It stopped the forum from working so I manually deleted all the ibproarcade plugins which seems to have fixed the problem.
However the uninstallation continues to time out and I want to make sure the hack is completely removed (including the arcade admincp menu).
What shall I do please?