Call up what is going to be your new template without the blocks ( or start a new drawing which you will later save as a new template)
Then while in that drawing do a :
File | Extract From
In the file dialog box that comes up click on the old template drawing that had the old blocks
Check the Graphics |Blocks box in the dialog that comes up. Hit the Open button. Should extract the blocks from your old (source) drawing and into the other target ( your new drawing) which you then save as a template.