I went through this with my old R32. It's a semi rigid urethane glue (similar to windscreen glue) and they have to use a cheese wire type tool to cut it. Have to be careful you don't damage the skirts but if the old ones are being binned, it's not a problem. It's a straight forward job for a body shop. Sounds like they just can't be arsed because it's more work than waving a spray gun around isn't it.