I'm looking at buying a used bike with this bottom bracket: "Shimano Dura-Ace External Bearing"

The bike currently has a Dura Ace 7800 53-39 crankset on it, and I plan to change it to compact. A couple of questions:

Is this an easy DIY? Any special tools required? For what it's worth, back in the 70s and 89s, I knew how to remove the cotterless cranks on my bikes and maintain/rebuild the BBs, but haven't done any of this sort of work in the past 20 years.

I'm assuming I can stick with the same front derailleur. Is this true?

If so, will there be major front derailleur adjustment issues? I have competence with adjusting derailleurs, but haven't actually installed / positioned one in ages. I'm pretty sure I could do that though.

Exactly what sort of specs should I be looking at for the new crank? I know the number of teeth on the chain rings that I want, but nothing else.

Any other aftermarket brands cranks I should look for (FSA, SRAM, etc.)? I'd like to stick to close to the same level of quality and weight as the current crankset, but am not married to Dura Ace or Shimano. I'm an avid recreational rider but not very strong and don't race, mid-50s and about 165 lbs. I probably don't need the absolute most durable/strong crankset, but don't want to insult the frame and groupset with a bottom of the barrel crankset. I'd like to stay reasonably light weight if given options.

Thanks, as usual.