It’s pretty easy to remove from Amazon. You just go to the Inventory section and when you click on the Box next to the items, and go to the drop-down menu right above the inventory, you will select “Create Removal Order”, and follow the prompts to do so. As far as I know, Amazon does this at a price of 50 cents per item.
However, I also have never heard of a service that really alters the product to allow you to send it back in.
If the product quality is no good, you may just want to have them all destroyed at a cost of something like 20 cents an item.
I have definitely had to do that with items before.
The other option is to donate them to some place that can use them (using a removal order).
I think if you remove the logo, it’s still going to be a bad product to sell, because unless you have a good reason to try to resell it, I would say it’s probably going to be a waste of time, money and effort.