Hi,
found it fairly easy to install the front bar using 'pre spanner' device that I made from bent metal bar, some clamps and a chain.
left side is pushed in really deep, right wheel is off and car lifted in front...
then, when the right piece of the bar is nicely adjusted, I added a spanner from the front of the car pulling the bar in on the right side, while I had a spanner (what's the best English word for this...'strap band' ?) on the left piece of the bar to pull it a bit out of the new bushing.
that "left pull out/right push in" made it possible to set the bar to the correct position, and install the underplate