I was able to change the ballast on the passenger side and both pair of bulbs without taking out the wheels, jacking up the car, nor removing the bumper.
I have a 06 e90 with sports package and I had enough room to change the ballast when I turned the steering wheel completely to the right.
The trick is.. I got a 1.5cm long hex bit that fit the screw for the ballast and used a wrench to turn it about 10 degrees per turn... It was a bit of a work, but eventually I was able to get the screw out.
The hardest part was taking out the ballast from the socket of the headlight assembly because there is a rubber seal and a screw that holds the ballast very tight from sliding out.
But I found a trick to that as well:
First you take off the HID wire from the ballast (it's hard, but it's possible. MAKE SURE YOURE NOT PULLING ON THE WIRE, BUT YOURE PULLING ON THE METAL PIN CONNECTOR)
Then just pull the ballast away from the headlight assembly, towards the drivers side. Don't worry about the other wire connector as it's long enough to handle this
Once you pull the ballast away from the ballast socket, and the rubber seal is completely out, slowly but with a little bit of strength, slide the ballast out towards the rear of the car until the second wire connector is visible from the outside of the assembly.
Once the second wire connector is visible, get a hook tool or something of sort to unlatch the wire connector before pulling it out. Once you get both of the connections out, slide out the ballast and you just successfully removed the ballast.
Make sure you take out the rubber seal band from the old ballast and put it on the new one if the new ballast does not come with the rubber seal.
Do the steps backwards and you can easily put the new ballast..
Putting the ballast in isn't as hard as taking it out..
It took me exactly two hours to replace one passenger ballast and change both of the d1s bulbs and it did not require me to do any wheel removing, jacking up the car, nor removing the bumper...
I'm sure a lot of people might not recommend the method that I used, but I was able to do the job without damaging the car in the end
