How do i remove trade post?

You cannot remove a post, but you can edit it.

Thank you for your time to answer, then ill jsut remove the text from the post i did and leave it like that.

Thank you!

When a trade is done, and you can still edit first post,
I usually edit it to "T/C" - "Topic closed".

If you forget, dont worry, you might get someone posting or pm you to check if you still got/need the item/do the trade, but after a set time with no activity, topic will be closed and moved to archive away from trading grounds.