you cant scale images on a bot and bots are not images. you have to use bots.
and you'd do %player.mountObject(bot, slot);
its not an image.
if you want to get a bot at a specific slot, do %player.getMountedObject(slot);
if you want to get the player (or vehicle) the bot is mounted on, do %player.getObjectMount();
to scale, you'd do the standard %player.setscale("x y z");
by default the bot when mounted onto a player will be facing forward. if it happens to not be facing the right direction, you can package Armor::onMount and fiddle with the bot's transform rotation parameters after calling the parent.