If you wish to completely remove your company's logo, you'll just need to follow the following steps:
Head over to Profiles > Company Details
Click on "Edit" on the top right
Check "Remove logo" box.
Click on "Save" on the top right.
To hide your company's logo in employees' payslips, just repeat Step 1 and 2. Thereafter, check "Hide company logo in payslip" box and click on "Save" on the top right.
In the event that you need to upload a new company logo, you can refer to the steps in this guide. 😁