I can't explain how to do this because it's in my head but when I have to make a call or something I keep putting off I can force myself to do it by kind of taking my brain out of the equation. Like for a phone call I just start dialing and by the time the procrastinating part of me catches on to what's happening the phone is already ringing and I might as well go through with it.
It's like the same brain mechanics that prevent you from touching a hot stove. You got to go out of your way to override or tick it since phone calls are also existential hazards.
I do the same when I want to start working on any task but it seems daunting or boring and I procrastinate. I just do the first step, like "ok just open the task's description, read it and try to understand the context". By the time I did this, I have no difficulty moving to the next step.