cut/get rid of section of drawing

Hi,

I need to cut out and get rid of a section of a drawing as per below:



The 'cut' tool does nothing. Unfortunately, I filled in the walls, which I can't unfil.

So, 2 questions:
1.  How do I get rid of this section?
2.  How do I unfill my walls?

Thank you in advance

You can't cut out a part of a drawing automatically by a shape like the rectangle.
If you still have the walls outline you can cut them with the Divide tool or use Trim. In both cases you have to explode the lines before if they are a polyline.
You can't cut a fill. Delete the fill and redraw it.
Depending on the geometry it might work to use Stretch to shorten a wall fill to the desired point.  

Oh wow dellus!
I had absolutely no idea that I couldn't do anything about my fills or ridding myself of unwanted parts.
I tried deleting the fill and zilch happened. Also tried changing colour from grey to white. Again zilch. Guess a fill is a fill.
Luckily I save each type of drawing - walls, windows, etc as different files.
I shall try the shorten tool.

Thank you for your response.
The volunteers at LibreCAD are what make it!

I've not read the devlopers code as have to get this out, but, if you know, what language is it written in?

It should be easy to delete a fill, click on it so it is highlighted, then press Delete. Or is it's layer locked?
You can change the colour with Attributes. Changing from fill to hatch with Properties leads to the hatch disappearing in V 2.1.3. Fixed in 2.2.0 rc.

I'm not a developer so don't know about the language.

OMG! It works! The fill disappeared. Tried and tried and failed miserably. Is the universe playing a part in all this?
Now I can delete/change/shorten the wall lines.
Tell you what - never, ever, do the pretty-pretties eg fill lines, before finishing absolutely everything else and checking it twice!
Hard lesson learned. It wasn't like that 20+ years ago. CAD was easy street then - point, aim and fire.

How do you know so much about LibreCAD? Disasters and time wasters? Must be - that's how we all learn.

When I finish what I'm working on, I'll have a look at the developers code and delve further.
I really need to repay the favours here.

Once again, with all my heart, thank you!

All the very best,

ps:
I'm copy/paste all this into my spreadsheet so my disasters never get a look at light again.
Reckon the language is C++ or C+ from the operation you described and worked.