If you want software assistance with drift alignment GuideMaster is free and has Polar Alignmment routines.
http://www.guidemaster.de/index_en.asp
WCS is designed specially for it:
http://wcs.ruthner.at/index-en.php
OR with PHD or K3 turn the graphing on - it is easier to see the drift quickly than via the ep.
Too much information!