For acccessing the files you must be on ROOT access
sudo su
Then access the list of IOS Simulators
cd /Library/Developer/CoreSimulator/Volumes/
When running ls you wont understand since the versions have mixed names
ls result
ls
iOS_23A8464 iOS_23C54
Enter the first one
cd iOS_23A8464
Now go to this folder where we can see the actually simulator runtime name.
cd Library/Developer/CoreSimulator/Profiles/Runtimes/
Running ls again you should see the version in plain text
iOS 26.0.simruntime
If it isn't the old version you are looking for get back to
cd /Library/Developer/CoreSimulator/Volumes/
And select another one.
/Library/Developer/CoreSimulator/Volumes/iOS_23C54/Library/Developer/CoreSimulator/Profiles/Runtimes