Flash upgrade for Cisco 871W

I would like to upgrade the flash on my 871w, adding a 32k module to bring it up to 52mb. I see conflicting information as to the procedure. Specfically once installed does all flash need to be formatted to recognise the full quantity. With the new addition does it fail and drop you to rmonitor at which you need to reset the register and format and load the images? I think I have most of it down, but the reset of the register seems a little vague from any documentation I have seen.