The P&E Protocol Plugin is the adapter used by the CodeWarrior IDE to talk to the P&E adapters.
It is a part of the CodeWarrior for CF installation (CW for CF 6.3) and cannot be downloaded separately.
So which version of CW are you using?
Why do you want to download the PP separately?
Are you sure you do not have it?
In case you already have it without noticing, you can configure it from within the CW ide:
Edit->Preferences->Debugger->Remote Connections
-> click add (or change while selecting an existing one)
-> select ColdFire PEMicro in the Debugger combo box.
Daniel