Hopefully I'm not going to write a book, but:
Firstly, I knew I didn't have a lot of room/ hence the Mini Drums.
I commenced by removing the tilt door and duplicating the space from the existing roller door, into which I managed to get the first door into. That is also where I uncounted the 1st problem. The Hanger brackets were too long owing to the roof beam. I loosened the brackets and tilted the forward to get the shaft above, the re tightened them. ( I modified the other door brackets by shortening them.)
I had measured and cut the shaft off both ends to keep the door centered. With that door in position I modified the the top of the tracks by folding the lip over and folding the top of the fixing back towards the door opening to make the door entry much smoother.
Getting the second door up was more difficult, owing to a roof support bracket fixed to the centre post. With a friends help we got the door onto the brackets and into the tracks.
When I operated this door there was a rattle coming from inside the drum. I lifted and lowered the door quickly, and finally a screw flew out from the Drum.
Some minor adjustments and I am very pleased with the operation and the look of the doors.
I would like to attach some photos but cannot see that option.
Thank you and your team
John