If you prefer playing PES 2016 with Manchester City and Arsenal instead of 'Man Blue' and 'North London', then you'll want your game to have the correct look to complete the visual transformation. Thankfully, it's possible to import kit designs, team emblems, competition emblems, and manager photos to do this, and process is relatively simple.
First, you'll need a USB drive to transfer the files to your PS4. To be recognised by your console this needs to be in FAT32 format, though exFAT should also work. Once you have your drive in the correct format, create a folder named WEPES to put your new files in. Next, you need some option files to import. There are many of these to be found by searching online, though the PES Gaming Forum is a good resource created by fans of the series.
With your new files in the correct folder of your USB drive, plug it into your PS4 then navigate through the game menus to Edit -> Data Management -> Import Images. Choose what type of image you want to import (kit, team emblem etc), then select your USB drive and tag the images to import.
Now go back to the Edit -> Team menu and choose the team or competition you want to update, before drilling down to the specific kit, team emblem etc and selecting the new image you want to replace it with. Repeat this process for everything else you want to update and your game will be fully customised to your own specifications faster than you can chant "Celery! Celery!" - congratulations!