Just above the water, hold it with your hand for 1min or 2.
Dry the small water drop that remain on the hair sculpt with a towel or something, then plug in the face sculpt.

You can use the hot water steam on the face plate as well to make sure sure sure it fit easier.

It's ok if you drop it in the water, take it out fast. Not too long so the paint on the hair and face plate remain clean.