dented roof!

someone at work today asked how I dented my roof - naturally I replied that I hadn't.
then I went to have a look - all became clear.
couple of weeks ago at a friends I tried to put the roof down and it stopped when nearly down.
then I realised i'd left a can of tyre sealant in the boot outside the pull out safety bit.
looks like the pressure of the roof going down on the thick can has actually forced a big dent into my roof
I shall try to photograph it tomorrow if the weather is nicer.
anyone ever done this? - managed to get the dent out?

 

there's an idea...... will try tomorrow