For a start...
1) do not leave ladders against the glass!!
2) do not use ladders on windows that height!!
3) do not use ladders on decking without safety device or someone footing!!
4) the multi panel glass feature could not be safely cleaned at all ...
TOO HIGH / WHERE WOULD YOU PITCH LADDER FROM WITH STAIRWAY / WHERE WOULD YOU POSITION HEAD OF LADDER.
5) WFP is the only way here
6) £40 with WFP
Them ladders look like DIY ladders...if they are, any insurance clain would be invalidated...seriously mate...change the way you are working...that job has DANGER written all over it for a ladder user!!