You can delete a model if you are administrator,
So if you are a administrator then click on your name on top right corner/ Go to manage models/select the model and then delete.
Thanks and Regards
Harish B K
One quick note on this, it is strongly recommended to *never* delete a model. Anaplan support is almost completely unable to help in recovering a deleted model, so this is an extremely permanent action. Since there is no impact on having Archived models it is recommended to just Archive your model, and possibly include a naming convention that helps you know which should be considered "deleted", this way there is no permanent loss.
Of course there are times when deleting a model is warranted, which may be your case here, so not to say you should never do it, just want to make sure it's documented here that 99% of times it is strongly recommended NOT to delete a model. Hope that helps!