How to properly animate a player interacting with an object?

I am trying to animate my player sitting down on a chair. I have a sitting animation working and I also have a trigger set up so when the player is close enough, it will initiate the sitting animation.

However, the problem my issue is caused by the colliders. I am using a simple capsule collider for the player. When the player attempts to sit down, the collider doesn't change shape, and therefore the player ends up getting 'pushed off' the chair. He's left floating in front of the chair in the sitting position.

What is the best way to go about this? I am going to have to animate many actions where the player will be interacting closely with objects.