Split keyboard, a key map printed out and placed under the monitor (so you Don't Look Down), and moving to colemak (without changing keycaps, that is the important bit - if you want to stick with Qwerty, just use blank caps). Plus a lot of practice with programs like GNU Typist, keybr, typeracer, ratatype, speedcoder, keyzen-colemak, typelit.io ...

This said, some things will remain hard probably forever, if you have a short pinkie like me.