Play on Medium with HC off, then practice just going on and off the ship over and over until you can do it without dying. It should take less than 10 minutes to master.
Use the fan far away from the core.
Walk off where the fan is, don't actually jump off.
Keep pressing jump while you're in the air. You get a second jump after a few seconds.
Keep attacking while you're in the air so you can't get stuck on enemies.
The best spots to get on the ship are NE and SW.
Once you learn it it's pretty fun, and it doesn't take long to learn. It's just super frustrating to try to learn it during a NMHC run, so I don't recommend doing that.