Thoughts:
Total of 10 screws to remove from rear of case (4 visible, 2 under riased rear feet, 1 per side - different screw size so keep them seperate, 4 under front rubber grip bar) Front rubber bar was easily removed by pushing a small flat head screw driver underneath it along the length and slowly teasing it off. Comes away without much issue and tape remained on the rubber strip for re-application. The rubber feet have raised plastic support within their depth, I removed this by turning the laptop upside down (front edge facing you) then slowly pushing foot towards you so it twists off, this required more force than the strip but it eventually gives without issue. Tape remained in position (some above screw) so needs slight cleaning once screw was removed but not a big issue.
RAM easily upgradeable, both slots instantly accessible
Hard Drive probably upgradeable but more difficult due to fragile wires than need removing prior to removal
Battery easily changed
CPU should also be upgradeale if supported Haswell CPUs become available