Originally Posted by krucifix85
take it down?
I think he means to test it before you permanently mount it.
There doesn't seem to be any way to remove a cracked digitizer from the mouning bezel without destroying it. Even though your glass may currently be cracked, I'm sure it still works at least. If you remove (and destoy) your digitizer glass, you won't want to discover that your replacement has the left and right axis reversed.
Disconnect the ribbon cable for existing (cracked) digizer glass. Connect the new digitizer glass. Boot your prime. Make certain that the new glass is the right model and the left/right is correct.
Even easier than that. Compare the rev numbers of the replacment digizier and the existing one. If they are different revs, you'll be hosed.