yes it is possible... you can do it by yourself... you have just to follow the guide until the step 7, replace your 128 gb ssd with another one...
be careful to buy the right ssd... on the very top of this page there is the bottom "PARTS", there you can find the ssd and chose the one that you prefer! when you have to reinstall the OS X, no problem because at the first start you can download it directly from the apple server!
Can i change the logic board of the late 2013 13" (i5 with 8gb of ram) with the new logic board of the mid 2014 13" (i7 and 8 or 16 gbs of ram)? Do they have the same pins and size?
i got the flash stuck in the camera and i don't know how to fix it. When i push the flash button the lamp does not came out. can someone give me a helping hand with out without making the process shown above??