[rbanffy]

For now, I'd suggest you just attach a bigger external HDD and enable Time Machine. ;-)

There is a fine guide on iFixit: https://www.ifixit.com/Guide/MacBook+Pro+13-Inch+Unibody+Mid...

[piocho]

Ok so what you are suggesting is to :

- create a time machine copy on an external HDD

- put the new SSD in the computer, restart it

- get the copy of time machine on the new disk

Will it be possible to reboot with the brand-new SSD inside the mac ?

[rbanffy]

No. The Time Machine part is for if everything goes REALLY BAD and for when you are reinstalling on the new hard disk.