how to destrip the thermal band in SLC_off LandSat 7 ETM+?

I am working on a special study in one of my subject.My study would require me to extract land surface temperature each year since 2007-2014. Since LandSat 5 cease to operate last 2011, my 2012-2014 data are from LandSat 7 with SLC_off. How will I destrip the thrmal band? I have envi 5.1. Hope you could help me!