If you can't find a lift, I would suggest starting from Shiel Bridge. The Skye bus stops there. The route from Shiel Bridge is described on here. https://www.walkhighlands.co.uk/fortwilliam/barisdale-morvich.shtml#:~:text=At%2033km%20with%20significant%20ascent,certainly%20be%20a%20welcome%20sight. ...