Can't afford to buy the extractor tool unfortunately. Plus thats the only bit on my drive thats needs re-doing.
I tried to use pointing trowel and chisel but the blocks are not moving and all. Think because it is at the bottom of a slow so all the weight and moved down and squashed against these blocks if that makes sense.
If you have a disc cutter, run the blade through the joints. This will take a small amount off the edge of the block making it loose enough to remove with a trowel and screwdriver.
Use a pair of trowels be careful they don't slip as you will hurts your fingers also try to get one of the blocks out at the highest point as these will be easier to get out (low blocks will be pinched tight due to the nature of blocks being longer due to different angle)