I'd offer a word of caution to anyone contemplating this who has not done it before. Just because some (or many) people have had positive experiences, doesn't mean everyone
has had a positive experience. If you can't afford to lose the chip and have to replace it, don't delid.
Now, assuming you can take the risk ...
IF you decide to use a razor blade, it cannot be stressed enough:DO NOT USE THESE:
^I used these on my 1st 3770K delid and destroyed the chip. Costly mistake. ^
What ultimately made a difference for the 3770K was using a thinner
blade, as mnasir is suggesting here for Skylake.
This thinner blade was able to slice into the adhesive on the same 3770K very easily. It all came down to blade thickness.So if you're going to use a blade, use THIS kind! It is thinner:
I had to look in 6 different local stores before I was able to find the kind of blade that I needed. Most of our pharmacies here no longer sell them, and I couldn't find them in the hardware stores or Wal-Mart-type places.