Can anyone tell me how to replace the pressure sensor?

This is a different model but very helpful. Enjoy

https://youtu.be/xRWScEE1GHU

I have not replaced it but the pressure switches I find on Amazon say you need to calibrate the switch. Getting that wrong will be dangerous so I decided not to. If get it "too high" then the pressure will be too high and possibly dangerous if the safety valve fails for any reason (like being jammed with food). If "too low" then pressure (and therefore temperature) will be too low and food will not be cooked as much as you expect.

Strongly recommend not replacing this part unless you can get original, calibrated, from manufacturer.

FWIW.

An Amazon seller has "GENUINE: From Genuine OEM Replacement Parts" pressure sensor, for fourteen dollars (12/2022). The seller also claims it doesn't need to be calibrated.

So, it's a matter of belief/trust, so as with everything YMMV.

Amazon being Amazon, there are no guarantees, however …

I bought one of the "Genuine OEM" sensors, dropped it in my dead InstantPot, and it worked like a charm with no fiddling. Assuming the worst, I ran it outside away from windows three times before I brought it back into the house.

I noticed right away that it got up to pressure faster with the new sensor so either my old sensor had been dying for a while or the new one was calibrated slightly differently. Either way, it's been working great for several months now.