I inherited a garage from my mother,

The right of usufrutto expires with the death of the usufruttario, so you are  the owner of the full property.   The only way you can not have the responsibility for the property is to sell it or give it away.    The man who is using it rent free, is there with no legal title it would seem,  but I would guess that if you want him out you will end up having to go to court.  He wants to keep using it but not pay a penny?  I think you need a stronly worded letter. 

Many thanks for your reply modicasa. The man is not using it rent free, as he paid market price to my mother years ago, but he never completed the atto to change the title deeds. It is therefore now in my name but owned by him, leaving me responsible for paying the taxes. As he is bankrupt he is not in a position to sort it out and I am neither in the position to sell or give it away.

If he has no atto he is not the owner.  You are the owner and he is occupying it with or without your consent.  Even if you are willing to let him continue use it, you should have a contract whereby he pays the expenses etc

This sounds really complicated! If you have not found the necessary help, I have contacts over in Italy. Where is the garage ? which City? Let me know if you would like to talk to a solicitor, friend of mine. She is amazing. But it depends where.