Here is the way to get to Borehamwood, if you are travelling from Waterloo, which I think will be quite a few people. Getting the 12:21 train from Waterloo is the safest bet as you are sure to avoid congestion from other supporters, and can get to the ground in plenty of time. There are also directions if you are travelling by car:
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1. London Waterloo 20.07.02 Walk 6 minutes
Waterloo (Tube) 12:16 Tube OL JL
West Hampstead (Tube) 12:35 Walk 5 minutes
West Hampstead Thameslink 12:44 Train Thameslink Rail
Elstree and Borehamwood 12:58
Duration: 0:48
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2. London Waterloo 20.07.02 Walk 6 minutes
Waterloo (Tube) 12:31 Tube OL JL
West Hampstead (Tube) 12:50 Walk 5 minutes
West Hampstead Thameslink 12:59 Train Thameslink Rail
Elstree and Borehamwood 13:13
Duration: 0:48
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3. London Waterloo 20.07.02 Walk 6 minutes
Waterloo (Tube) 12:46 Tube OL JL
West Hampstead (Tube) 13:05 Walk 5 minutes
West Hampstead Thameslink 13:14 Train Thameslink Rail
Elstree and Borehamwood 13:28
Duration: 0:48
Take the A1 towards London, then take the second turning on the left, (at the bridge). Go over the bridge, then follow the sign the for Town Centre. Carry on straight at the two mini roundabouts, you should then see the Police, Fire, and Ambulance stations on the left. At the next roundabout take the second exit (Brook Road).
About one hundred yards on the right is a school, with a public car park immediately after. From here You can use the Brook Road car park (pay and Display), and enter the ground at the Willow Tree end, or if you wish to use the club bar, take the next turning on the right after the car park and follow the road around. The entrance is on the right.
From London Fiveways corner (where the A1 & A41 merge) Follow the road until you come to Mill Hill roundabout go straight across and up the hill, at next roundabout turn right, third exit signposted A1 the north, carry on straight at next roundabout, and when you see a bridge turn off at the slip road, (signposted Borehamwood) and head for the Town Centre, and continue as directed above