Solved! Go to Solution.
Solved by steven-g. Go to Solution.
"one thing to watch out for though is that it can change the new inported block into the old"
more like; it DOES change the new imported block into the old...
and that is exactly the problem. im sure thats why this question was asked and none of these answers indicate that it is possible to do.
at this stage i am deleting all instances of the block concerned, then purging the drawing, then dragging the newly modified version of the block in from another drawing using design centre.
This thread is 10 years old, Use design centre, make sure your old drawing is the active one, go to the new version of the block in design centre and right click on the new version of the block, The sub menu will let you 'redifine' or 'insert and redifine' the new block to replace / update the old block.