The DIY swaps for Macbook hard drives is very easy. I've done many, and the longest part is waiting for the hard drive to be cloned.
Use CarbonCopyCloner (freeware) and a 2.5" enclosure to copy to the new SSD.
Have a set of precision screwdriver and torx bit handy as per iFixIt guide.
Takes about 10 minutes (or less!) to do the swap carefully.
Boot! That's it you're done.