THERE MIGHT BE SPOILERS!
(I reset the campaign 2 times)
First try:
At the start i got help from my friend who told me how to double jump, craft grenades/explosive spears, told me how to use checkpoints and said that i have to go to FP.
I decided to go trough the leg but i wasnt really sure where to go since i didnt know where i was in sahded citadel so i just went randomly and somehow found myself in the checkpoint near memory cripts, after going trough them in just half a cycle i slept in the first checkpoint of the leg.
After I woke up i learned that instead of The Rot there were these little bitches that look like red spiders that shoot tranquilizers at you and eat you whole so after some shenanigans with them i said "Hell nah im going trough chimney canopy!" And reset.