Park a few meters east of the Jura Creek Trailhead (mining entrance) on Highway 1a. The trailhead should be just on the right of the logging road.
I took my wife with me the first time but we only got to the final ascent to DoorJamb. Our way up became strenuous because we stayed left of the trail... far from the ridge. After coming accross a dead end, we decided to just descend straight down to Jura Creek and hike back to the car from there.
(1) I came back by myself and I made sure to stay on the ridge this time. I got to DoorJamb with no problem. This cairn was knocked down possibly by the wind, so I rebuilt it.
(2) Here's the way up to Loder Peak from DoorJamb. The wind was very strong on my entire trip so I had to step away from the ridge once in a while... but made sure to stay on the right track to avoid another dead end.
(3) 1:30hrs to DoorJamb, then another half an hour to Loder Peak.