You will need to go in through the back, and remove the movement.
First off set the time to 12.
Remove the caseback
Pull the crown out fully. Then you'll see a small nodule on the crown side of the movement. Place a small screwdriver firmly, but not too hard on this, and the crown stem can then be pulled out and removed.
Then there are a couple of screws around the outside to remove, this is the movement holder. Then the movement can be removed, and it comes out in one piece, dial et all.
Im not sure how you could refix the lume, but this is the easiest way to get it to that stage.