You have mentioned that you want to move the stock from blocked to QI or to Unrestricted. Why?
I mean you just want the stock to be used again? Or You want to reverse the original material document of 101 movement that created this lot?
In earlier case you can very well bring it to unrestricted from block using 343 movement type using MB1B. But in later case you should implement the note 175842 to cancel the movements made through inspection lot. This will bring the stock back to QI against the same inspection lot and then you can very well reverse the original 101 document.
Anand