Each shipment contains assembly instructions and a diagram of the foundations.
To install the bars, you need a spade, a spirit level, a mixing tank to stir the ready-mixed concrete and tools to tighten the screws.
Larger units should be assembled by at least two people.
If you prefer to arrange for a professional to assemble the unit, many customers have used a local gardener or specialist gardening service who can handle the assembly for you.
Please take a look at https://www.galabau.de/FachbetriebSuche.aspx, where you can obtain a list of suitable, local businesses by entering your postal code.