alternate mode help needed

Ok, I made a stupid mistake. when I made one of my characters I forgot to pick a Alt-mode and how can I pick one?
is it possible?
is it possible?

SEIBERTRON - Your Planet For Everything Transformers
https://www.seibertron.com/energonpub/
https://www.seibertron.com/energonpub/viewtopic.php?f=16&t=48843
Absolute Zero wrote:upgrade character. Scroll down. Alt mode list.