how to resdt computer on 2017 subaru forester

Only with a dealer quality scan tool or have a good shop do it for you. If you disconnect the battery then you could loose all the memory then you will need it towed to a dealer and have it reprogrammed.

What if you are in the country battery dies you call road side assist.They remover battery and put in fresh battery you start and drive away. Happened to me, did not have to recode ecu.

Then your one of the few that got lucky or you didn’t notice they hooked up a unit before hand. There are little ones that plug into a power port and only use a 9 volt battery, they are for very short term