About resetting the computer and where to put the key

What is your question?

A friend of mine took her 2008 A3 to an auto tire repair shop to get a new fuel pump put in. I told her it would be a big mistake but she went for the lesser money. To make a long story short the monkey didn't know what he was doing when he messed with the electrical system when he was running a service check and he tripped her computer and it says the top is not secure when it is closed and it will not open. I know where the key is and I know it goes somewhere in the trunk but I do not know where. So can I PLEASE get some info help on these two problems. I don't want to have to take it to the dealer again this will be the fourth time in 5 months.