stannah model 420- carbon brush ?

Not too bad though you have to be an acrobat to do it.
Remove the stop ramp at the top of the stairs and also the end cover where the wires connect. Use a remote to run the chair up to the top, (carefully) so it passes partly off the rail but remains attached. Take a hold of the chair as the Brush box passes the rail end as it will want to fall forward (The brush won't like that ! ) Need a set of TORX Drivers and undo the Two screws retaining the brush box. A smaller Torx driver for the wire lug and the box is free. Refitting a reverse of removal but when you run the chair downward, Support it so the brush is not compromised when it engages with the copper strip (Power OFF obviously) then carefully let it fully settle back to normal position and then remove the small pin (which has held the brush up) and the brush will contact the track strip. Should be good to go when you re-fit everything else you took off.

Leccie
September 2020