removing bound SDS from protein samples

Hi experts,

I need very pure protein for FACE analysis. As last stage I'm going to use purification from SDS-PAGE: cut out single band from the gel and then extract protein. I'm afraid that SDS (still bound to my protein of interest after  extraction) will interfere with PNGase F digestion (though reaction mixture contains SDS at final concentration 0.05%). Could you, please, suggest method to remove SDS from my protein sample after extraction SDS-protein complex from gel ??? By now I have found only info on GeBa kit, but it needs lots of buffer substitutions, and I could end up with unsufficient amount of protein.

Thank you,
Larisa