One tip - if you use the split tool that the vendors supply to drive the old bushings out, stick a flat blade screwdriver up in the other side of the spindle to keep the two sides of the split tool spread apart while you drive the bushing out.
Also, the new bushings will need to be line reamed once they are installed. The vendors sell a line reamer that works well.
Replace the bushing on one end of the spindle, then use the old bushing that is still in the other end to guide the line reamer. Once the first side is reamed, then drive out, replace, and ream the second bushing.
If you have already removed both bushings so that you no longer have a guide for the reamer, the vendors sell a guide:
The spindle with the new bushings will likely be too tall to fit in the end of the axle. The vendors sell a tool that can dress down the high spots in the axle due to wear and also dress down the spindle bushings so that the spindle fits in the freshly dressed axle space:
If you only have one pair of spindles to do and you don’t want to buy all of the tools, Snyder’s offers a spindle rebuilding service. You may still have to dress down the high spots on the axle ends and dress down the ends of the new bushings to get the spindle with the new bushings to fit in the axle opening.
Oh, and I am assuming that you may or will buy new kingpin bolts to go with your new bushings. If you buy the bolt set, it comes with new bushings: