[tobeychris]

There are basically three ways to flash your diamond.
1. Run the RUU with your phone booted (running WM).
2. Run the RUU with your phone in bootloader.
3. Press Power + VolDwn + Back + Reset with a ROM named DIAMIMG.nbh in the root of the Internal Storage.

1 allows things like a sSPL to be run first to allow a hSPL to be applied.
1 requires at least 50% battery life.
1 shows your current ROM version and the future ROM version.

2 has no battery requirement.
2 shows only future ROM version.

3 should have no battery requirement
3 does not show any versions, but does show what aspects are included in the ROM (will only say OS since we only flash Operating System ROMs here really)
3 can be done anywhere as long as your image is on the device (but if it's just the one you already have on there, it would make more sense to do a Hard Reset).