JayADee: I'm not using flexible pipe, I'm using 90 mm thin wall, solid pvc. Like the 60 and 80 mm kind on your downspouts.
I don't know how to hook the pipe up to my access pit without it being stuck there with zero slope.
Connect the pipe to the 0-degree fitting. Gently heat the pipe near that fitting with a hot-air gun until it softens enough to droop/bend down to create the shallow angle you require.