Right then, here goes.
Difficulty rating out of 4 out of 10
Time taken about 3 hours so far and I've only fitted 1
Worth it? Oh yes!!
Total cost(inc tools) approx £150 so less than buying bars new and saving whatever BMW charge (around £500)
Flat and phillips screwdrivers.
16mm Socket and driver
Allen key set
Step drill bit
Dremel or equivalent with metal shaving bit
Torx key set
Shot of whisky (this is optional but you are about to drill big holes in a perfectly good roof)
Start by removing all ceiling fixtures such as sunshades, interior light handles etc.
Next loosen/detach front seat belts using 16mm
Remove pilar fixtures and tops of door seals
There are little plastic pieces in the top of rear side windows, remove these and any sunroof trim
Drop roof liner out and remove
Now locate the threaded bolt points by removing the 2 front gromets
I used an allen key to push through bolt point and create a dimple on the roof to act as a marker.
Next the fun bit, take the drill and 5mm bit and go for it, dont worry if its not dead centre, using the step drill enlarge the hole and direct it as required to centralise
Using the dremel and bit shave the hole bigger and create the little lug points for fixture
Next using the torx keys attach the first fixture in place
now marry rail up to it to locate the next drill point and repeat process
Lastly marry up again and find rear points, repeat process again, bolt on fixture and then fit rail.
Step back and admire