The RAM involves taking the bottom off and shoving in some more sticks. Officially this can only support a maximum of 8GB but I have had no problem with 16GB.

The RAM involves taking the bottom off and shoving in some more sticks. Officially this can only support a maximum of 8GB but I have had no problem with 16GB. For the hard disk, it is fairly trivial too. Follow iFixit's guide: https://www.ifixit.com/Guide/MacBook+Pro+15-Inch+Unibody+Mid+2012+Hard+Drive+Replacement/10761 https://www.ifixit.com/Guide/MacBook+Pro+15-Inch+Unibody+Mid... I went with a Samsung 850 EVO 1TB.