This will be my 8th vegan Passover. While many of the items on the Seder plate are already vegan (Karpas, Maror & Hazeret), here are some replacements for the ones that aren't.
Charoset recipes may vary and already be vegan as is, but some people use honey. Instead of honey, I like to use maple syrup.
Instead of the shank bone, you can use beets.... or if seeing the representation is important to you, you can use a plastic or toy version.
For the egg, I've seen many ideas depending on one's interpretation. Some options are an avocado pit, edible flowers, boiled potato, wooden egg, or an orange.
I hope these tips are helpful and wishing my Jewish friends and family a Happy Passover!