I had to buy a new PS3 after my first one got the yellow light of death. I was actually excited about having to replay all my old games to build up my trophies again. I was even more excited about the possibility that all the annoying games and trophies I had accumulated with my first PS3 would be gone. I hated having the dead weight of PSN downloads that I didn't use.
I logged in on PSN today and found out that all my old crap is still there. Annoying downloads, trophies I don't want, all of it, was still there.
Can anyone tell me how to delete information from my PSN account?
To erase the trophy data from your account, you'd have to delete the account entirely to start over. Trophy information is tied to your name forever; there's no way of cutting yourself off at the leg to abandon these prizes.
Games you've also bought from the store or demos you've downloaded in the past will retain their place in your account information via the PlayStation Store's account archives. If there are certain games on your download list you don't wish to download again, you don't have to. If there are games on your hard drive that you don't want, you'll just need to delete them (in this case, you'll need to press the triangle button over the item + the selection of delete).