From Temple of Time, paraglide north to the 2 boulders, Stasis Boost in the north direction (add a bow hit for more distance), when it starts slowing down land and spawn Epona. When climbing Epona, press the camera twice to turn her in the right direction, and go straight to Hyrule Castle entrance, using Infinite Horse Sprint if available, and Slab Launch.
From Temple of Time, paraglide north to the 2 boulders, grab Hyrule Grass, Stasis Boost in the north direction, the chain 3 Stasis Boost via trees. Grab the attack body armor in the chest on the way.
Teleport to Magnesis Shrine, Stasis Boost with the Box nearby, land on a 4speed horse (RNG), they have 3spur and max 2 color. Travel North with Infinite Horse Sprint, go for a hole in the wall on the right of the main entrance (the horse will jump if you go via the side opposite to the static Guardian with the right angle). It is also possible to use a box launch slightly east on your way north with the horse.
All these routes converge to the Slab Launch described in the video below :