I should mention that I did this twice. The first time was see where the hole locations should be. I then removed the landing gear and drilled 1/8" pilot holes in it with my drill press. Then I re-aligned the gear and drilled those pilot holes through the stringers in the fuselage. Even though I used 4 clamps to hold the gear in place, I also used 1/8" bits, AN3 & AN4 bolts to place in the holes while I enlarged the holes to their final size to accept an AN5 bolt. The idea here is to make sure the holes stay aligned while you are enlarging the other holes. Here are a couple of photos.
Click on image to enlarge
I had seen in other builder photos indicating one needs to be aware of possible interference of the side bolts that hold the side angle support in place between F3 & F5 bulkheads. I happened to be using pan head screws instead of countersunk screws at these locations, so I will be able to remove these screws temporarily to install the gear bolt nuts. Here are a couple of photos showing this situation.
I just noticed that I have mislabled the locations of these bolts. They are the right side, but I have the forward/rear locations reversed from what they should be.