There are two ways. The second just cuts out a few steps.
For example, if you want an Aeanoid, you would need
The instructions have an option to talk to Vanya. This will take you to his workshop, and he will ask for certain items to make a toy from those instructions.
You can skip the toy making step and buy a ready made toy from user shops, such as .
Either way, once you have a toy of the Nostalgic pet you want, take that toy and [item2=Essence of Melody] to Vanya to change your pet. It changes the ACTIVE pet, so make sure to have the one you want changed active! :)
I think that's everything. It's been a while since I made mine.
You need to make the pet you want colored active.
So take the plans and kit to make the toy of the pet you're after (or buy the already made toy if a user is selling it). Check to be 100% sure the active pet is the pet to change. Take the toy and essence to Vanya and then you'll have your new pet after confirming.
FINALLY GOT THE 15K WARDROBE DONE!!!!! Next up gutting and selling it.