re-Jailbreak atv2 & other questions from complete newbie

Legacy 2nd gen Apple TV
1

Hi

I have an ATV2 which I bought jailbroken with XBMC, Nito TV on it.  I have no idea what method was used to jailbreak it.  I also have no idea what software version is running.  People talk about version 5.0.x and 5.2, 5.3 etc.  My atv2 is obviously out of date cause I get a lot of messages saying link broken or just won’t go in and gives me a red circled x.

 

  1.  How can I find out which software version I have?

  2.  Can I rejailbreak it and install ATV black on it - basically treat it like it’s new and starting from scratch?

  3.  I will be doing this on my mac.  Are there any notable differences between mac and pc methods?

  4.  Can I do serious damage doing this myself?  What pitfalls to look out for?

  5.  Buying ATV black is it a software licence for only 1 atv2?  I have 2 of them, but one of them is really giving me trouble.

 

Thanks and I hope someone can help me!