Relatively easy to assemble , mostly requires body weight to piece things together. That or a rubber mallet should do you fine. 

Some of the instructions aren’t as clear as they could be, (mainly the positiondirection of the second metal bar that you screw in) but you can figure it out with enough patience.  Ours ended up under a covered patio, so I can’t speak to how weather proof it is, but the shelf on the inside is adjustable so you can have a really large top drawer, small drawer, etc. The unit is slightly larger than anticipated but it works well.