To upgrade from the previous version of the class, perform:

0) Replace \documentclass{beamerikz2} with \documentclass{beamerikz}

1) Find and replace in case-sensitive mode: 
  \bzCoords    -> \bzGrid

2) Remove uses of \href

3) Move all \node, \draw, \coordinate, etc commands inside \bzOn, \bzIn, ...

4) Pay attention to flow of \bzH, \bzI, etc in content which disappears

5) Replace \bzUnder with \bzOn[-1], \bzIn[-1], etc