[JohnyLondon]

I went to update to the latest version of openelec for my raspberry pi2 but inadvertently put the pi1 file in the update folder. Now it wont boot (stuck on colour splash screen) and I cannot access it from my other machine to correct matters.
Assuming I'll have to do a new disc image on the sd card?
Just put the sd card into the other machine and it wont recognise it

[Milhouse]

You'll need to extract the KERNEL and SYSTEM files from the Pi2 tar file and copy them to the FAT partition on your SD card - rename KERNEL to kernel.img, and delete the overlays folder (as it will now contain Pi1 overlays). That should be enough to get you booted, then perform the upgrade again using the Pi2 tar file in the Update folder to get you back to normal.