You can't really!
All you have to do is type in your email adress and password that you used for the deactivated account!
There are 2 ways you can delete photos.
1. Go to the photo you want to delete and go to the bottom right hand side and press "delete photo"
2. Go to the album that the photo that you want to delete is in, then press "edit albun" at the top, then press the "edit … Read more