is it possible to take my mac-mini to the apple store to be upgraded? I was thinking about hard-memory upgrade....

I've got a basic mac-mini and I'd like to upgrade it (to make it faster once I owrk with imovie which is quitely demanding)

I thought about hard memory upgrade (once I have a MAac-Air wich is much fastar than the mini).

Is it possible to take my mini to apple sotre in trder to have it upgraded?

Thank you.