How to flash BIOS on Lattepanda V1?

I have recently bought 8 Lattepandas. I bought 5 more used and they are not able to boot at all.

All of these are "Enhanced" models with 4GB/64GB. S70CR700

I have 3 that work but the rest don't. The three are Lattepanda S70CR200 (One has dead EMMC but I have been able to use flash drive for that).

If possible, do you know where there are instructions to 

A: Reflash the BIOS

B: Replace BIOS chip

C: Get BIOS chip repaired or flashed by someone else.

I understand that there have been countless posts but they all seem to not have any useful info. Some posts start off with some steps but do not finish. Some posts have guides and links to dead post. Lots of posts seem to have "unavailable" pictures which I cannot see.

Thank you.