Deleting red datum cross

I am preparing some drawings for laser cutting. How can I delete the red datum cross and also the round small red datum point used with lines etc.?
Another question, is there a fillet tool/tab?
I was having problems with semi circles, but found the "s" shaped tab and "three points" tab very useful.

These red absolute zero and relative zero symbols are not a part of the drawing file, just indicated by the cad system, and will not appear on a print-out and do not affect any laser cutting.

Tools - Modify - Fillet. Watch and set the Tool Options bar for the radius and whether to trim or not.

Thanks Dellus.

 I now can do this, once I realised that the radius has to be added.
I am not sure how to use the trim tool ?
Mike.

Do you mean the Trim Option for fillet? Excerpt from the manual:

 1.14 Modify Fillet with Trim Option
Commands: fi, fillet
Prompts: Specify first entity
  Specify second entity
Bevels and Fillets: selecting one of these two will prompt little windows below the horizontal icon upper line, the tool options, they allow to indicate either the bevel dimensions or the fillet diameter. Many other icons will prompt tool options that will allow to add properties to the command.
At command entry a Trim tick box option opens on 2nd icon bar (above drawing area):  
• ticked - removes lines projecting beyond fillet;
• unticked leaves projecting lines alone.  
Note Window labelled Radius
• type 0 produces standard trimmed corner.  Perhaps as Trim2 command.  
• type 1 or more is radius dimension of fillet.  May need to zoom in to see action.
Follow first prompts then pause and see options shown for location of fillet by moving mouse.  Then specify second entity.

Or do you mean the normal Trim command? From the manual:

 1.9 Modify Trim
Command: tm, trim
You type command on the Command line.  
Prompt: “Select first trim entity”.
 “Select second trim entity”
Curser shape changes to a 'hatched cross' and when you select first line to change it turns to a different color.
Command line prompts you with “Select second trim entity”.
The two lines shorten (or extend) to meet at a 90 degree angle.
• When lines are to 'shorten' ensure you pick the part of the lines you want to keep, not the part to be trimmed off.
• Hold down Ctrl key when cutting the first line to cut more than one line.
• Command appears to either 'Lengthen' or 'Shortening' lines as needed.
• Stays in command until Esc key pressed.
• I prefer Trim 2 command to the Trim command.

The manual:https://wiki.librecad.org/images/2/20/LibreCAD_Users_Manual_2.1.3.pdf

Many thanks Dellus. I will have to work on that. Needs a few hours practice I guess.!!
I have found that in order to do good workable drawings for laser cutting, the best plan is to zoom several times to large size, because then you can clearly see any gaps or faults in lines. If the laser sees a gap it stops cutting and it does not understand what to do next. In addition, any measurement lines can also cause problems. Double lines , where one has been drawn over another also cause problems.
The laser company I am dealing with at the moment prefer very simple drawings with only basic dimensions.
Mike.

This is enlarged view of part of a drawing that was thrown back to me from the laser company.
At normal size this looked ok.