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.
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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.
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In the event that you need to upload a new company logo, you can refer to the steps in this guide. 😁