If I wanted to remove the translation request, I'd first have to reject Porfyhr translation, and as it seems to be a good one, better accept it and tell this young guy that next time such a translation request would be removed.
(so this is English courses during the holidays, uh? means this young guy needs to improve his English if he wants to be able to follow courses in the upper class...)
"to crack his head": Casper, I think that "quebrar a cabeça" meaning "to think too much in order to find a solution for something" only exists in Portuguese... It's an idiom, unstranslatable as is.
I know it.
But, e.g. 'blue blood' was an idiom only in Spain till the first half of the last century but now exists also in english and many other languages.
I think they will understand.