GB update, Root/Unroot?

[Amorak#AC]

Question 1
Is the process described here for update of Froyo to GB?

Question 2
Assuming Q1 =Yes, then what I would like to do is:

1.) Root
2.) Titanium Back-up
3.) Unroot - needed???
4.) Install GB per Q1
5.) Restore via Titanium if - needed.

So, my question is, do I need step 4? Or, can I just install to rooted phone?

Thanks,