programming the pic preview on posts in a twentytwelve theme

hi,

on my site:

https://www.travelwithcastle.com

i’d like to make two edits. any guidance is appreciated.

1) i’d like to link the pics on the post previews on the homepage to the actual post — when i click the picture, in addition to when i click the title text. right now, it only goes to the post if you directly click the post title text. i’d like to also link the picture preview.

2) i’d like to delete the enormous preview pic that shows up on the actual post page at the top of the post. that pic is already within the post content, and there is no need for me to have it up top as well.

thank you