Reading on here, the throttle body clean on the DE is no big drama but the HR has the potential to make the ECU go bananas. MAF is delicate, copy what someone else on here has done before without breaking it . I'd personally disconnect the battery and pump the brakes a few times before touching any of it, but some people like to live more dangerously.
There's a load of threads on this, copy this into google and fill your boots - site:350z-uk.com clean throttle body
DISCLAIMER - you breaking anything is nothing to do with me, for info only here!