Which arms have you bought? The Meyle kit comes with the wrong nuts for the balljoints so you need to buy the right ones if thats what you have.
The silver-green one is for alloy uprights, which is what Meyle comes with. Those nuts don't fit the steel uprights so you need the black ones instead. The black ones are 4D0407644A or Febi 15905.
Also, most kits come with the wrong pinch bolt for the upper arms, so check what you have vs what comes out. We can deal with numbers for that depending on what you have.