Boxer BB AC drain tube blockage

Greetings.

I have an 1980 512 BB. I was out for a spin in 90+ F weather and 90+% humidity. My son noted the passenger carpet was damp. A quick check did not show any water draining on the ground. So my AC drain is blocked.

Can I get at the drain tube "easliy" by removing part of the under tray or does it all have to come off?

Thanks in advance.