How do I replace the motor in a Polti vacuum cleaner AS805?

I have a Polti Lecologico AS805 vacuum cleaner that I have hardly used and is just out of warranty The vacuum cleaner now sounds like a more like a scooter and gives out a really strong burning smell! Is it possible to replace this myself, as I have been told it will cost £60 for the motor alone then with labour charges on top it will not be worth doing. This will be such a shame as the vacuum and its parts are just as new.