You sure can. Log in to your account at any time to edit the contents of your grüum kit for future deliveries.
Change your kit contents: just head to ‘your grüum plan’ and choose the plan you want to view. You can then select ‘edit my kit’ to pick and mix from any of the products available on site.
You can also remove unwanted items, add new items and increase or reduce the quantity of individual items in your kit.