I found this information extremely hard to find. When Daedalus first came out, you had to run a full node and that downloads the whole blockchain and takes up far too much space for anyone’s personal computer.
Here’s how to delete those pesky blocks.
On the Finder’s menu bar select Go
1-Click Go to Finder…
2-Type ~/Library/Application Support/Daedalus
3-Delete the content of the DB-1.0 folder