Removing cube shapes from extruded text

Hi There

Im having problems with an effect im trying to achieve. Basically, i have some extruded text, with floating “pixels” hovering above it. I’d like to create the sense that some pixels have been removed as blocks from the text…I come from a design background, and thought that converting the text to a mesh, then using a boolean (difference) could remove the chunks i needed from the text. I ran into some problems, and after reading some forums, realised that it was due to the bad geometry left after using the boolean modifier. Someone suggested removing doubles, which worked to some degree, but got a bit messy…I 'd like perfect cube “holes” left behind in the text, but the geometry is not right for extrusion.Sorry, im a total noob, im sure theres an easy way to do this, i just dont know where to start ;(Thanks in advance

You can also remove some of the bad geometry by using limited dissolve. There will still be a lot of cleanup needed.