Can you transform an already existing pet into a steamwork pet?

Yes, you can. You still need the schematic for the kind of steamwork pet you want and a yunium key, then bring them here (link) and it should give you the option to create a new steamwork pet or transform one of your existing pets.

If you make a new pet, it will get the special Steamwork/Cog gender option. If you use an existing pet, it will keep whatever gender option it has at the time.

Thank you so much