I'm going to replace my harddrive in my MBP with a new SSD. Currently the HDD is running OS X Mavericks (10.9.5) but I would like to install macOS Sierra on the SSD. As I would like to start from a clean install I'm thinking of following the solution suggested on iFixit: https://www.ifixit.com/Answers/View/264094/How+can+I+install+OS+X+on+a+new+ssd Basically it suggests: 1. Download the OS installer from the Apps Store. 2. Plug in SSD in the MBP using a SATA to USB adapter. 3. Run Disk Utility to partition the drive with GUID and format it with Mac OS Extended (Journaled) partition. 4. Run the installer selecting the SSD drive. 5. Check it is working correctly (reboot MBP holding Option key and select the SSD as the boot up drive). When I have done this I'm thinking of transfering my stuff from the HDD to the SSD and then finally replace the drives. If I follow these steps, will I be able to transfer my stuff from the HDD to SSD like I would normally do with an external harddrive?