Leave the parking heading north for around 1km and keeping the power lines on your left. When you reach around 2176m, head north-west under the power lines into the Combe SE which starts to steepen with boulders present at the bottom. Skin up this until at 2424m where you cross the Col du Galibier road.
Head north-west at an easy angle over small gullies and mounds. You should soon see the pointed summit of the Pic Blanc du Galibier. Follow the steeper slopes to the top, depending on conditions either via the south face or the south-east arête.
Follow your tracks back to the parking.