Webasto Airtop 2000 STC Clog and Repair

My Webasto gasoline heater stopped working after running at high elevation for a while with no altitude adjustment. The amount of soot inside was tremendous. I had to replace the burner unit but it's working well now.

The video I watched to help me is:

[robertutley]

To be clear you don’t have to take the blower Motor apart like this guy lightly touched base on.(the T25 bit for the long screws on the front facing with the white ring securing the red and brown wires around 3:15) he didn’t clarify that you don’t need to do that and if you do you might have a really hard time getting the magnet seated properly which will then lead to an H89 blower/fan motor problem.

[MrMariutz]

Good job..what the part nr for the new one?

[ataata]

Where to buy the parts from?
Mine has not been maintained for last three years but still works fine

[GuruBoards]

How do you put into high altitude mode?