After its hot enough, use a thick guitar pick to peel back the broken screen from the frame. Be careful, it may be hot and glass could get everywhere.
Once you've removed the old screen/digitizer, apply new adhesive on the frame and put the new part on. Make sure that you get the old adhesive peeled off. We recommend heating the adhesive before applying the new screen for better bonding.
That's it! Now, follow the steps backwards to reassemble your device. Congrats! You've replaced the screen!