replace_initrd.mips, null-linuxrc.img.gz kernel

[soapm]

What are the step by step instructions of copying the kernel from the stock drive using Winmfs. Running replace_initrd.mips, null-linuxrc.img.gz then putting it back?

I see it is easy to back up the kernel but it seems to be in a compressed format. How do I decompress it to run the files on it?

Is there a replace_initrd.mips, null-linuxrc.img.gz process for Windows? With step by step instructions?

How do I re compress the kernel back to a format Winmfs likes so I can insert it back on the Tivo drive?