No special access issues
1) No special rules, other then normal common courtesy and common sense.
2) Drive from Bø towards Lunde. Take a right where there is a sign to "Tveiten". Drive on a asphalt road for a few minutes through farmland area. When the asphalt ends and the road splits, take left. Drive on this gravel road for a few minutes. Eventually you will reach the parking which is just before the bridge over the outlet of the Uvdal lake. There is also an info sign by the parking.
3) From the parking, walk along road on the right side of the lake (not the road with the bridge). After 20-30 meters, go straight right into the forest. Inside the forest you should find a diffuse path that leads uphill. Walk along the path. Eventually you will see Veslesvaet to your left after a few minutes.