Usually to do this I use a pry bar and hammer or a bonzai bar, but in cases like this where there is an aluminium bracket being held firmly against the wall it's tricky to know what to do without risk of blowing out the masonry from the face of the blockwork. I would like to avoid doing this as much as possible as there are quite a few of these and I intend to paint the wall once cleaned up. Any damage will be filled with external masonry repair. Views and opinions welcome.
