Deleting a morphed line that is connected to the other morphed object as a one

[paveko]

Both line and morphed roof show as one object, thus I can't select only line to delete it. I have tried using boolean operation subtract but when I click on it it says  'non-solid elements were not subracted'. When I click on solidify it says that one or more elements couldn't be solidified. 

What else should I try doing?

URGENT

[Barry Kelly · Accepted solution]

Set your selection to to 'sub-element' selection (I think CTRL+SHIFT is the keyboard shortcut while selecting - it will toggle between a white/black cursor).

Then select just the line and delete it.

If you can't delete it, you can set it as a 'hidden' line in the morph settings so you can't see it.

Barry.

[paveko]

Thank you, the first option worked.