I misplaced an item (built an armorstand away from the training area) and i want to move it to the correct location. How do i do that? I can't seem to dump the item, remove etc?
Use the q command to view the built object and when you have it selected, press x to remove the construction. The dwarves will deconstruct it and put it back in the stockpile.
Then just rebuild it in the correct location.
Note that if a dwarf is performing the task of moving an item to a stockpile it will be considered "in use" (and the item will be marked with "TSK") even before the dwarf reaches and picks up the item. You won't be able to select it for rebuilding until the task is not active due to completion or cancellation. You can forbid item within before deconstruction, or you can forbid the item to cancel the hauling job. Afterwards, while paused, unforbid the item and rebuild it before the hauling task is assigned again.