| Hello Julio,
You may definitely delete a tab icon, or replace the current one with a transparent .png file however, it is most likely that in case the tabs lack in tab images, the app will get rejected by Apple Review Team.
For an instance, in order to change the tab icon image, you need to access the dashboard of your app and then go to "Design Properties".
Here, you will be able to see the sectioned to select the icon images for each of the 4 tabs available.
Do the needed changes and make sure to click "Apply Changes" and then "Done".
As an alternative option, you may simply upload the needed tab icon images to the resource manager of your app. Then, access the app.xml file directly and change the file name pointed in the path to the tab icon images.
In case you experience any technical issues with changing the tab icons from your app, we would kindly ask you to open a support ticket with us for further assistance.
Best regards, Ethan | 
