On the homepage of your environment, you can click Modules on the left-hand side. The different modules will then appear as green tiles. Click the General tile.
Then click "Companies" on the left-hand side.
By clicking "Details" on the right-hand side next to the name of the desired company, you will see an overview of all company details.
By clicking the orange "Edit" button at the top right, the company details can be changed.
After editing the details, click the green "Save" button. You will then return to the overview of all company details.