Just got done delidding my 3570k and putting together a new test bench today. Here's my story, apologies for the rambling, really tired and spent a lot of the day worrying about this
I originally knew I would go the razor method because I am really good with my hands, but at the last moment I tried vice method and managed to slightly warp, scratch the sides a lot, and I even chipped a small piece of the pcb covering layer on the bottom edge near the contacts, luckily it stopped right before exposing the copper plain underneath and it booted and runs fine so far. I used a very precise expensive vice and still had issues.
I am not here to argue the merits of either, but I quickly went back to my original plan and spent about 30 minutes carefully prying through with my blade.
Blade ftw that's all I am going to say, no cuts, no dings in the upper pcb, the die is fine etc... contacts are fine.
I used CLP, just covering it as instructed, mirror sheen etc... and replaced the cm tim to Prolimatech PK3. One thing to note is that I just used a qtip to apply the clp, but I don't think any fibers were left behind.
Strangely my idles are exactly the same, and I tested with same cooler and %100 fan rpm same as before, maybe someone has the answer to that riddle.
However under full P95 test for 20 minutes, load temps are indeed 15C less, so it was worth it, and thankfully the block of wood that chipped the lower pcb covering didn't brick my chip.