Merging Files on a Mac

Hi, I'm using a Mac to play FM for the first time & I'm finding it difficult to merge files together. Especially for the updates to the Megapacks and Logos, how do I merge the latest files with the current ones without replacing the current files? On the Mac, it asks if I want to replace all the files with the new ones. Please help. Thanks!

Both the megapacks you mention will include both new and improved images. In the case of improved images, they will improve on the existing images, so you should confirm any overwrite warnings

That I do know. But it's different on a Mac where there's no option to merge but instead it replaces the old file with the new ones. No overwrite option as well.