For the moment you can only change by the Detail Button (Up right page corner )
but not that you want...

For that you want use the Dimension by Max Smirnov
http://moi3d.com/forum/index.php?webtag=MOI&msg=7403.133

You will can Separate anything! (that you can't do now with the native Dimension that you have used)
So erase Start, End arrows etc...