Easy.
-Remove 3 bolts for the gas tank hose filler. Drop the tank some with a jack and a flat piece of wood. 2 bolts hold the tank straps up. Take off the straps and pull the tank over towards the drive shaft. This will allow enough room to get your hand inbetween the tank and frame rail to install the bolts.
-Remove the front leaf bolt and drop the leaf down along with the axle.
-Grind the rivets off and remove factory hangers.
-Install the drop hangers.
This next step is huge and will save you a ton. I never see anyone do it this way maybe because they follow the instructions? I'm not sure, but below is the proper way imo on how to install the hangers.
-Cut the leaf spring bolt shorter so you can install it from the outside in. This will allow you do bolt the hanger on then put the leaf up. If you don't do it this way you will have to install the spring into the hanger and fight to get the 6 hanger bolts in (or 4 depending on drop hanger).
That's it.