You place them, but of course only one will be in the right position. So, to shift the others, remember one block is 0.5m. the .bp file is written in meter units. So if you want to edit an engine rightward, increase the x value under "position". With x values, be careful to leave the comma or your file won't load again. To shift left, decrease x. Objects to the right have larger x values. To shift up, increase y. To shift down, decrease it.