Crazy paving

A small demolition hammer drill will do it, but what will you replace it with? When I had a MASA house it was put on to cover up damp! MASA were good at covering things up.

I want to change them to tile

Sds drill with chisel bit will do the job, then use a resin solution painted on to bond a cement render to even everything up, then a final skim coat of "monocapa". This is self coloured and comes in a variety of colours, white being the one of choice for us.

Retiling is an expensive way of doing things simply to change the look of your house. -   If the existing surface and grouting is sound, a much cheaper option is  just painting it over. Looks good,  especially in a darker colour e.g. pale  grey.  Lasts well, and the rough texture is not bad looking either.

Lived in Portsmouth too long for light grey to be a colour of choice 😁