how to change buttons

I know thisis probably very simple, but I cant find it in requently asked questions.
So wouldapreciate help please, I want to change the 'new messages ' 'no new messages' buttons
when I have made my buttons how do I put the new images in place of the old ones.

Do you mean the Navigation link? Go to "General / Homepage / Nav Links", click this icon nearby the appropriate entry and paste your image-links into the "picture" (no new messages) and the "secondary picture" (new messages).

It is the ones that show new post or no new post,
the ones I have arrowed in the screen caputure
This is all an adventure for me you can see my forum, I want to have an empty flower pot and a pot with a plant growing instead of the red and green discs I have now. Or something like that anyway.
http://todgrow.forumandco.com/

Ah, that would have been my second thought.

Those can be found in "Styles / Pictures & Colors / List of Pictures". Switch to the "Forum icons" tab and you will find the entries there.

brilliant thanks, I shall design new buttons over the weekend.