So how will the buyer get it home? Especially if the six-figure sum includes the garage?? I think we should be told. Or mebbe the buyer hasn't thought about that? https://www.theguardian.com/uk-news/2019/jan/18/banksy-artwork-garage-wales-sold-six-figure-sum
It's a block wall. Remove a few roof panels, take the blocks with the image on and replace them with new ones, put the roof back on.