Philips 42PF7320 buffer heatsink removal

[tibimakai]

I would like to attempt replacing these chips on the buffer boards(all of them) since the whole screen has pinkish lines.
I'm a beginner in smd soldering also, but I would like to learn. I'm getting the tools needed also. I'm in the process of buying a hot air station.
Last time I have tried removing one of the heat sinks after watching a Youtube video by twisting it, I have ripped off the heat sink with the chip together and ruined the board of course. It seems that it's glued there with thermal grease.
So this time I would appreciate some help from the pros.

[tibimakai]

Re: Philips 42PF7320 buffer heatsink removal

I have removed them using a hobby knife kit. I have just pried them off, putting the blade between the chip and heatsink.
Last time I have attempted this I listened to a guy on Youtube and I twisted off the heatsink with the chip together, ruining the whole board.
Next step is to remove 12 chips. I'm waiting on a hot air de-soldering station that I have ordered from Amazon, the model number is Kendal 899D.
I have purchased 15 chips for $40(!) from Ebay.
Anybody attempted this before? I would have another question, to re-attach the heatsink I should use regular thermal compound and then use hot glue around the heatsink to hold it in place? That is what this guy is using on Youtube, but it doesn't seem right to me. I'm thinking to use thermal glue and forget about the hot glue.