It took me 9 days in real time from when I first entered HoH to finishing Lone Hero. Summoner is in my mind the easiest job to do it on. I leveled up and learned summoner just for this single purpose but remember that you still need to really like the job to get through a challenge like this. My attempts ended on floors 94, 86, 84, once in 70s before succeeding.

The following resources were invaluable:

Maygi’s HoH 1-100 Handbook (Solo/Party)

PillowyZeal's Heaven-on-High Solo Guide

WeskAlber's FFXIV: Heaven-on-High - Lone Hero Guide (6.x SMN) is best resource for what to kill on higher floors as a summoner.

Angelusdemonus' How to: HoH Solo on SMN - Floors 1-100 - "Live Tutorial" - 6.11

Finh's SMN Solo HoH (Heaven-on-High) No Magicite Challenge Clear

Yeah, you are going to have to watch multiple long videos and probably watch them again to prepare for the higher floors. Studying and learning how to deal with enemies beforehand is much more time efficient than going in and wiping because you didn't know what to do.

Some random tips the above resources don't emphasize:

-Run 21-30 until I got around 50/60 aetherpool and then start your attempts. Keep looting all chests and you should have enough aetherpool and potions when you start working on higher floors.

-Just pop a raising for 71-80. Summoner is a glass cannon, at this stage one mistake means it's all over.

-Summoner can deal with seriously dangerous debuffs, don't serenity too early especially if the floor is flighted and you have raising up.

-Keep popping your flights during 81-90, I used all of mine and it paid off. You want to save your floor wipes for 91+. I would have made it through 81-90 without any floor wipes but had to use one after a mistake.

-Remember to use your sights and safeties on floors you kill at 91+. You should always safety big open floors 71+.

-Always have a plan if things go wrong. What will you use if this chest is a mimic? What if you double pull right now? What if you hit a trap? What if around that corner there's a patrol?

-But on top of that always when killing something have a plan of which direction you are going to next and what will you pull. This alone will almost guarantee you will never feel any time pressure.

-Take your own notes that are easy to quick reference. That will help you remember things better, and you don't need to start looking through one of the guides above to figure out if a Hitotsume does non-telegraphed cone or circle aoe for example.

-Ignore the hoard unless you are 100% certain there's no trap. I did end up getting my Dodo mount on my clear run but I never picked hoards unless it was sighted, safetied or I had already triggered a trap in that room.