Dumping the microcode into a bitstream can be done in an automated way if you have clear, high-resolution die photos. There are programs to generate ROM bitsreams from photos. Part of the problem is removing all the layers of metal to expose the transistors. My process isn't great, so the pictures aren't as clear as I'd like. But yes, the hard part is figuring out what the microcode bitstream means. Intel's patents explained a lot about the 8086 microcode structure, but Intel revealed much less about later processors.

I do this stuff at home. I have an AmScope metallurgical microscope; a metallurgical microscope shines light down through the lens, rather than shining the light from underneath like a biological microscope. Thus, the metallurgical microscope works for opaque chips. The Pentium is reaching the limits of my microscope, since the feature size is about the wavelength of light. I don't have any training in this; I learned through reading and experimentation.

One tidbit to add about scopes: some biological scopes do use "epi" illumination like metallurgical scopes. It's commonly used on high end scopes, in combination with laser illumination and fluorescence. They are much more complicated and require much better alignment than a regular trans illumination scope.

I suppose you might be able to get slightly better resolution using a shorter wavelength, but at that point, it requires a lot of technical skill and environmental conditions and time and money, Just getting to the point you've reached (and knowing what the limitations are) can be satisfying in itself.