On 03/06/2018 13:53, wrote:
http://i64.tinypic.com/30k8yts.jpg Normally I'd gently angle ground
round a brick to remove it, how can I get the job done in this case?
The downpipe is cast iron and can't be left disconected.

I'd wait until you can remove the pipe and replace/return it.

An SDS chisel can remove the mortar and the bricks if replacing them.