I would not rate this as a difficult task and I managed to complete the dismantle and reassemble within the 45 Minutes, Overall a pretty good description. The hardest bit was reattaching the wifi wires. I found I did not need tweezers and used a small electrical flat head instead of a spudge. No soldering or other tools. Having bought a new battery and charger (circa $50) the replacement part ($5) and this guide solved the issue. @gifts.fromgod my part was not identical (colour and size of the mid wire join) but fitted more or less and works a charm.

Missing step. The hard drive needs to be removed. 4 screws then slide back (to left in above image)

The reattachment of these wires is tricky and not immediately obvious. The wires clip to the card by a small circular attachment male on the card female on the wire. I used a small flat head electrical screwdriver to push down the wires onto the card.