FCPX Multicam Editing - How do I trim unwanted dialogue?

I'm doing my first Multicam edit but have been stumped. I have three camera angles and a separate audio track. I'm fine with going through the timeline and cutting/applying angles - all good, great in fact!

But there are some parts of the timeline that need removing (retakes, stumbles etc) - the "normal" ripple trim option doesn't work. So how do I do this? I absolutely can't leave this stuff in and to be honest, feel a bit dumb that I can't figure it out.

Hopefully someone can help me, thanks.