Of the tube walks this channel has done, this is one of the most straightforward to describe.
Instead of turning left out of Cockfosters station, going down Cockfosters Road, then 1930s-built Westpole Avenue nearly all the way to Oakwood station, we turn right out of the station.
This is a bit counter-intuitive since this takes us in the wrong direction. But no. Past the cemetery up to the gates of Trent Park and then entering the park, you are rewarded with a glorious walk all the way to outside Oakwood station.
The only requirement is to be able to map-read your way there. Not to difficult if you remember to keep the tracks of the Piccadilly Line to your right as you walk.