what he is trying to say is rather easy.
1st. get your trader flag on (thieves can not summon transport in towns...

duh)
2nd. dismount and make your stall and put all the stuff in and CLICK OPEN!!! I HATE IT WHEN NOOBS FORGET TO OPEN THEIR STALLS!!!
3rd. after your stall is done simply click mount, and hooray, your stall is on the transport
