Long walk near Dorking

I've got a day off tomorrow and I'd like to do a long walk/hike. Ideally I'd park up in Dorking and do a large loop, with the total walking time being around 6 hours (can be more).

Alternatively I could park at Friday Street but can't picture a loop route from there.

I'd like to be deep amongst the trees for most of it!

Thanks in advance for any suggestions.