How do i get rid of old outbuildings? I have a 1940s wooden cottage which is great. 

It has a matching wooden shed and kindof lean to. Both need to go. The lean l-to is piled with old timber i pulled out of the house during reno. Some native, most junk. How do I get rid of all this? Noxious weeds have grown through and over it all.  I want to clear the section. Is this a demolition job,  a builder or a landscaper? Its too much for me too handle alone.