First things first: If you think .pdb files are only used when debugging your application locally and are not needed when deploying production binaries, please read the following article by John Robbins: PDB Files: What Every Developer Must Know.

Welcome back, still interested in getting rid of the .pdb files?

Follow these steps:

1- Select Project Properties > Build Tab > Output section > Click Advanced button.

2- On the Advance Build Settings window > Output section > Debug Info dropdown: select none.