In order to edit a block in draftsight, all you have to do is doubleclick on it, he following windo will appear:
Review the window, and click OK.
When you are done, you can either use CLOSECOMPONENT or SAVECOMPONENT to exit the EditComponent command.
Well, as far as I know you can not get AutoCAD for free (at least legally).
But there are options, you can get free alternatives that work very well, these are my favorite CAD software replacements:
For 2D CAD you can use Draftsight, it’s free -as free beer- for personal use, it can open/save DXF aswell as DWG files.
For 3D CAD you can use FreeCAD, it’s free -opensource- , it can open/save STEP and IGES files between others.
For Architectural CAD, CYCAS is a very good option.
Sometimes it’s necessary to convert text to lines in a CAD system.
For example to use the file in a laser cutting machine.
The command to do this is: EXPLODETEXT
(DESCOMPONERTEXTO en Español)