So i've been playing close to 4 years now and primarily heavy metal and stuff. I've always been able to grasp techniques pretty well but one technique that still sort of baffles me is pick scraping... It looks so easy when i see others do it but i just can't seem to figure out how to do it?

The big problem i seem to have is once i'm done the pick scrape when i go to lift my pick off then i get a very noticeable ringing from the strings and not to mention i can't seem to transition well into the next part of the song.

Any advice would be very appreciated.

Thanks in advance
Make sure you've got the angulation right. If you're coming in at a right or actue angle, you won't get a good sliding sound. I find that an obtuse angle helps me to get a good sliding sound and is easy to transition to.
Geldin got it right.

Also, you don't have to travel down the whole neck, or even over the fretboard. I've seen some people slide their pick across 12+ frets, but this isn't necessary. I usually do it over the bridge pickup or in between the two pickups. This way, you won't have to move your hand too far back to it's original playing position. Also, if you do the pickslide slowly, you'll only need to slide a couple of inches or so. It'll be more or less the same sound, so you don't need to scrape the strings across half of the fretboard.

In my restless dreams...
I see that town.
Silent Hill.
You promised you'd take me there again someday.
But you never did.

Well, I'm alone there now.
In our 'special place'...
Waiting for you.