Under format choose Mac OS X Extended (journaled) and click Erase. Click Erase tab and chose name for new device, I recommend to name it SSD, so you can clearly see difference in next steps. Connect new SSD drive to Mac if not done so yet, and select it on left in Disk Utility.

Now you have to prepare new SSD drive.

Macintosh HD) to resize to size smaller than new target SSD disk.

On the left now select primary disk it self (Type Logical Volume Group), and on the right select Partition tab, click + sign and drag primary partition (e.g.

Open Disk Utility, locate your existing HDD and select primary partition on the left (mount point /, Type: Logical Partition), this can be named Macintosh HD and in First Aid click Verify Disk, to make sure you are error free before start.

Reboot your Mac and immediately hold Cmd+R during POST stage (black screen). Do it to external HDD or Time Capsule device. You need: 1 SSD drive and USB SATA adapter, it can be any enclosure, or SATA to USB adapter cable, or if you have thunderbolt or any faster connection this is even more preferred. This solution does not require any reinstall, all the way setup of user account and Mac settings, or separate programs or much more time consuming operations than direct disk to disk data transfer. The fastest and most efficient way can be done completely using standard tools in OS X. Clone larger HDD drive to smaller SSD drive on Mac.

Can you clone a mac drive to an ssd