If you can find the replacement ball joints it is possible. I changed out just the ball joint in the front lower. Maybe its the same just need to press it out and measure.
Just found a local BJ manufacturer, who has professional garage to do all repairs. Price is approx. 18 EUR/BJ plus 25 EUR total repair cost and additional 25 for wheels adjustment. That's 122 EUR total, which seems very reasonable to me.