Can you delete part of a mask

Hello!

Been working with anolder version of camera raw for years, so I am kind of new to masking (whuch by the way, WOW!)

My question is, can you delete part of it, like you would do with a brush?

I am attaching the zoomed in example photo i am working on here, and as you can see, the mask goes beyond the arms, and I would like to adjust that. Is there a way to do it? An eraser-like feature?

Thank you in advance for tips and ideas!