So, since the switch from PS4 to PS5, everyone can now re-earn their achievements…but appears you can only 99% it…and you must use a brand new character to earn them. However, there is only one exception…buying 20 vanity items from Crazy Earl. If you already bought him out, you’re out of luck on buy 20 more the 2nd time around. I did see we got 3 new Echo Skins however…17 more to go… Is there plans to add some more Crazy Earl vanity items? I did see the Body category added in his shop. This could be a very possible thing to get from him too. The body options have been really cool.
If you bought everything on all four characters, the only way is to backup your save, delete and start from scratch. If you join Slaughter in coop, that 500 eridium brick should be enough to buy what you need, so you can do it in few minutes.