Surprisingly couldn't find any videos of a strut change on a C, but it's pretty much the same across models. Found that Prius C strut mount (pic 1) doesn't share the same 3 bolt design (pic 2) in other prius models. I ordered complete strut assemblys and it came with a warning sticker over the top bolt saying not to remove it because it could cause serious harm obviously. Am I incorrect, is the only way to continue to take off this top bolt? Is there anyway to remove the strut as a whole, without compressing the spring and dissembling the whole assembly?
The Repair Manual (available by subscription to techinfo.toyota.com or in the ChiltonLibrary service, to which many public libraries sponsor access for their patrons), under Suspension: Front Suspension: Front Shock Absorber: Removal, explains how to remove the front shock absorber with coil spring from the vehicle as a unit. Compressing the spring for disassembly is done later, with the assembly off of the vehicle. The shock absorber rod supplied by Toyota has two nuts threaded to it, as shown in the parts catalog (Figure 48-03, Front Spring & Shock Absorber). The top nut secures the assembly to the vehicle, and the bottom nut—which must not be removed unless the spring is compressed, of course—holds the assembly together. The manual says both nuts are non-reusable parts. When removing or installing the nuts, the manual says to keep the shock absorber rod from turning by holding a hexagon socket wrench (6 mm) inserted into the top of the rod. When installing the nuts, to achieve the specified torque values, the manual calls for a special service tool, the lock nut socket 17 (09729-97202), and explains how to calculate the correct torque from the fulcrum length. The SST is needed because an ordinary socket would keep the hexagon socket wrench from being inserted into rod; you might be able to use a 17 mm offset oxygen sensor socket instead. By the way, if you decide to buy the Toyota coil spring compressor tool specified in the manual, note that its part number has been changed. As of Service Bulletin S-3002 of August 2013 (available by subscription to toyota-tech.eu), 09727-30021 has been replaced by 09727-30022 (list price now ¥93,100), with an improved, safer design. The bulletin gives other instructions on using the tool and also describes a coil spring stopper belt, 09727-00110, which can help keep the spring from flying off if something goes wrong.
Some of the few dealerships offering a 09727-30022 for sale around here are quite optimistic about the price the market will bear. Compressor Coil Spri 09727-30022 | Frontier Toyota