Reset Fuel Trims MY17 Astra

Can anyone on here tell me how to reset my ltft, have had the car back 5 times to rectify a slight misfire, actually had it throw up a code of P0172 which they just cleared and did nothing else except suggest bad fuel, what a load of crap as it has always run 98 from the same servo, under load on a hill it can get to the point of running on 3 cyl, why it doesn't throw up a misfire code is beyond me, I wish to reset the trims to see if it makes any difference, it is not a coil pack or maf as these have been eliminated by checking with a multimeter when I replaced the plugs, tired of dealing with dealerships that don't give a dam with the attitude of no returning code no problem, any help appreciated. ps it also ides rough as I do not run the auto start feature.

Used to do that with an Opcom on the older Astra's or pull the battery off overnight. Worth a try taking the battery off.

Thanks Dutchy, the battery trick didn't work will have to go through the software and see if it can be cleared from there.

So what about an ELM obd bluetooth adaptor and for instance the Torque app ? Not sure if an Opcom still actually works on the newer cars.

I have a old tech 2 that I am getting updated, been retired for nearly ten years and its way out of date, may as well put it back in use, was just wondering if there was a back door hack that worked. Cheers.