Cant believe how stiff the destination blind handle is on 52417, you cant even wind it properly - its too stiff to turn and you end up scraping your knuckles at the top where the cover door closes. From my point of view the tension bar where the rollers fit into on the left hand side needs loosening, i only had to change it from Norwich to Lowestoft, the tension is far too tight and blind will end up tearing before long. Why is the light so far down, on all other 156s you cant see the light for the destination blind.
short term solution
I have found a way of loosening the tension whilst you wind the blind, i know its a short term measure but it makes it easier to change, the tension bar on the left where the rollers fit into, in the middle of the tension bar push it slighty and keep it pushed in whilst you wind, this releases the tension whilst you change the destination. I found that it worked for me.