I know a good method.
I got mine in and it was used but it did not have the x-clamp fix or the red light problem.
I had turned it on for around 5 minutes and the rear fan port area felt hot as a hair dryer.
I thought geez no wonder there burning up so fast and I thought to myself I dont even trust this and doubt I would get an hour of playing in before it burns it self up.
so I ordered a x-clamp fix and some arctic silver 5 even know it did not have the 3rol.
as testicale stated that he would never dream of doing that well he probably wished he would have did it before it even started and if so would never have the problem to begin and now hopes it does not happen again down the road becuase prevasive action was not taken prior.
The stock heatsink actually dont even toach the chip like there made to there is an actual gap between the heatsink and the chip wich actually defeats the whole purpose of having a heatsink on there in the first place when left stock.
the x-clamp kit makes it sit and toach like it should be in the first place with the correct amount of force to pinch the heatsink and chip togther tight enough wich the stock clamps could never do.
the arctic silver 5 replace's the stock tar like play-do that actually was a waste to even put it on them to begin with and it contributed to the heating issue instead of helping it.
so I got my parts in took it apart and had cut out the rear fan grill on both the metal case and plastic case why?
it actually takes 12%-15% of the air flow away becuase the grills block the airflow somewhat.
the metal fan grill was removed becuase metal gets hot from the exuast heat constantly blowing on it

and holds heat so all that stock hot air heats up that metal grill and it holds it and after awhile the whole damn thing heats up like its a giant heatsink so by removing the metal fan grill it allows the airflow to improve and also allows heat to escape and not be passed around the whole inner console becuase the whole frame is warming up.
next thing to do is add two small wire on the motherboard to make the fans run at 12V constanty. it is loud but they can also be set to 9v wich is a tad more quiter and still a way better improvement over the stock setting.
the aftermarket fans are junk and have burned up and caused damage in various ways to themselves the console case motherboard etc. the stock fan mod is the best fan kit really becuase it can be ran at 12V safely.
then you need to take a piece of poster board and masking tape and lay it where it covers your gpu heatink completely and connect it with the masking tape to your fan shroud.
for the CPU side you do the same but only cover half of the cpu and connect it to the fan shroud with masking tape.
then tape the sides where the heatsinks meet the fan shroud I also did where the fans meet the shroud just to get in that extra bit of suction.
then you download the cutout piece that gets placed down the center of the fan shroud to point the air where it needs to be instead of sucking from every direction this way it is focused on where it should be drawing from.
when left stock the air only gets pulled from the front 20% of the heatsinks and the rear barely get any cooling or suction strengh from the fans at all with this method it does the gpu 100% and around 90% of the cpu side.
by sealing this up like this it make's it have more of the vacuum effect where the air is sucking out much better and now nothing is restricitng it anymore now that the grills were removed.
heat rise's but it will not catch fire and with this method it does not get hot and it also sheild your dvd drive from getting to hot if it were left stock there have been known instance's where the gpu got so hot it ruined the dvd drive that site right above it.
there is also a Co-GPU kinda like the orignal xbox's MCPX chip if you add a heatsink on there it will drop it 4 degree's gaming and 7 degree at idle/dash over stock.
but after I did the x-clamp kit with arctic silver 5, cut out the fan grills and added the 12 volt wires and the poster board trick with the shrouds I now can play for hours and when I place my hand back there now it feels like I am running a A/C unit in there.
the change from stock to now was just unbelievable on the difference it made for cooling it went from hair dryer hot to feeling like a A/C unit.
all parts needed can be had for under $20.00 and you will get your moneys worth for sure by doing these easy upgrades.
when you get the heatsink off to do the x-clamp kit use arctic silver 5 instead of the stock play-do I forgrot the actaull specs on the improvement over stock but I think it was around 17 degrees.
add them all up and it makes a huge overall difference when compared to stock.