You can do it, as you have started the blog. In the 1st blog, click the "Tags" button and all the tags (Trains, stations, locos) will show up. You will be able to see "XXX" buttons on the right hand side of each of them. That is the tag removal button. Using that, kindly remove the wrong loco tag. Even after the removal, if the correct loco tag doesn't show up, then add it once more using "Actions" button.