Here’s the process of removing and installing the tantalum capacitors. They sure are a pretty good fit. I’ve used case size D instead of case size C. Either case size can be suitable where the electrical specifications and board footprint permit it. The larger package here is really a consequence of the capacitance, voltage rating and capacitor series I selected, rather than derating itself automatically requiring a larger case.

First power on with the new capacitors installed. There are 9x 47uF 25V (case size D) and 2x 100uF 16V (case size D) installed. Note the lack of fire! ;)

For more context on the derating rule I was using at the time, see Apple Macintosh LC 475 Derating Tantalum Capacitors.

Sources

• KYOCERA AVX - Voltage Derating Rules for Solid Tantalum and Niobium Capacitors - explains why derating guidance depends on capacitor technology and application.