There are lots of different ways you can do the Ranmore to Downs Link section. It's best to go along the bits you know, and just piece them together.
It's kinda tricky to describe the route we did, but we went along the top of the hill (on the NDW I think) aiming for Gomshall, then crossed over the A24 and went towards Peaslake. At Peaslake we went up Pitch Hill to the upper car park, then over the road and up the next little bit of hill to the windmill, to join the road. Then we pretty much took the road all the way to Cranleigh so as to save time. (We were 6 minutes behind schedule at that point and I was starting to get a bit worried...
)
Elliot's suggestion is a good one, easier to navigate, although longer. But with the rain we've had recently, the sand should be firmer so not too tough.
Also, I vaguely recall thinking that the Downs Link could be pretty tiring in the wet (as the surface is made up of mud along many parts of it) so might be worth thinking about that!
More than happy to chat through some route options if you want.