I have received my real logo, how do I replace it?

Short answer: Upload the new file into the existing logo rather than creating a new logo: every product that uses it follows automatically.

Steps

On the “Shops” page, open the “My logos” tab in the left-hand panel.
Click the thumbnail of the logo you want to replace: its detail sheet opens on the right.
On the image preview, click the small icon at the top left of the image — the one that changes the file — and pick the new file, SVG or PNG.
Check the background (“Light” / “Deep” / “All / I am not sure”) and the quality shown once the logo is saved.
Click “Save”.
For each shop that then shows an orange banner, put the logo changes into service: on the “Shops” page, select the shop, click the orange button (its tooltip reads “Modify the shop (create a draft)”), then the blue button with two checkmarks (its tooltip reads “Put the logo changes into the current shop”). If a draft of that shop already existed, that is what opens: the change is already in it, and it goes online with “Put this draft shop into service” — see I changed my logo but the shop products do not show it.

Keep the same logo name: what is attached to your products is the logo, not the file. Replace the image inside it and every product follows on its own.

Already created a new logo for the final version?

No need to go back through every product one by one. Once that new logo is approved, delete the old one and choose the new one to replace it: every product that used the old logo switches to the new one, in all your shops. See How do I delete a logo.

For a new file, replacing the image inside the existing logo is still the most direct route: the products follow without you having anything to choose.

Going further

How do I change a logo on every product of the shop — the two ways to change a logo on all your products, and which one to choose.

You'll know it worked when: The products that used this logo show the new image, with no reconfiguration.