Default [Q] M7: upgrade from cm 10.2 to cm 11 milestone

hi,
- is there a step-by-step instruction somewhere on how to upgrade a m7 (plain GSM, no provider) from CM 10.2 to CM 11 (i didn't find anything in the cm wiki which seems to target exclusively new installs)?
- cm wiki mentions a CWM recovery update -- is there a way to find out which version is used from within a RUNNING phone?
- since the M7 does not have an external sd-card -- is the part treated as sd-card safe or will the upgrade delete everything on it?

Thanks

ps: just found a thread saying that you need to flash both CWM recovery update and the CM kernel at the same time to prevent a boot loop -- doesn't seem right to me when the CM update should work via the built-in updater?