If you need to get it into Pr without re-capturing, then try the free eac3to converter:
Download eac3to 3.27 Free - Convert E-AC3 and TrueHD audio tracks to AC3 or FLAC - Softpedia
or
eac3to 3.27 - VideoHelp.com Downloads
GUI:
Eac3to and More GUI - Doom9's Forum
Jeff