How do i delete my old threads?

How do i delete my old threads?

Why do you want to delete your old threads?
if they remain inactive they'll just disappear into obscurity at the back of each cue.

So people dont get confused

replace the first post with a link to the thread you want people to go to.
again, the threads will disappear pretty quickly if there aren't any new posts in them.

make one sales thread and update it. maybe start a new thread every 3, 6 or 12 months.

Yep, if it is a sale thread just keep one and update the content. Updating content does not move it to the top though so add a post in it that you have updated items and your thread will go back to the top.