It's usually done by firmly massaging into the area. I just stumbled upon this channel so I dunno if Dr. Kim goes into detail but Chiropractic Medicine (aka Dr. Brent Binder) makes this a regular thing in his videos and even explains how to reach it. Some other videos are out there which basically explain the same thing. It's a massage that you can even do on yourself to get the ileocecal valve active if it isn't.
