Parking are available in Watts Gallery (GU3 1DQ) during their opening hours (they do shut the gates), or perhaps in front of the gates if they are shut.
The round walking trail close to Chantries Hill is simple https://ezekiellevh508649.goabroadblog.com/27944136/little-known-facts-about-dog-walks-where-they-can-swim-guildford