Q: Shock mount bushing replacement

Generally, if a bushing is captured within a spring assembly, then yes the spring has to be compressed, the top nut removed and the part replaced. However, I would need to know the exact model to let you know if any sort of unique (model specific) tools are required. If the shock has 100,000 miles on it, though, it is likely worn. Consequently, the required repair might indeed be to just simply replace the shocks on both sides. If you intend to work on it and are not sure of which type of spring compressor to use, consult the Factory Service Manual. I would let you know, but I need the model of vehicle. If you want the shocks replaced by a certified Mechanic, dispatched by YourMechanic right to your location, please request shock replacement and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.