Well you can't remove your own posts. Only Moderators and administrators can.
But you do have a few options:
1) Tell us were it is and we can remove it.
2) Post under it tell others it is out of date and what has changed.
3) Any post you have made can be edited. Go to the post you want to edit and the "EDIT" button will appear right below it. I have uploaded a picture to help you.
Oh and thanks for the complament.
Rumas