Check post #73 in this thread. It's not an 8GB patch - it's a patch adding support for SDHC cards which should in theory support card capacities between 4GB and 32GB.

You need to use the Linux flasher and flash only the kernel. Seems to be working OK - I had a single reboot within 24 hours of applying the SDHC kernel, but in the 3 days since then it's been stable.