Summarized tips/tutorial.
Material,60W soldering iron ( if need to buy locally since all DX and such are selling is top of the crap )Solder paste,a standard heat sink not too big with a central path around 22 mm, iron wire to hold it tightly, look the pics in the thread, a tiny tweezer which can hold securely the small ceramic substrate of the emitter.
An emitter victim to practice, postpone the real one after when the confidence reigned
Skip the wood box, the thermocouple and the broken heating element of the thread, once the heat sink is attached hold it horizontally with a vise .
Unsolder
Put the star over with some thermal grease behind to improve the contact. Power up the soldering iron and wait patiently ( three to five minutes ) . Look carefully, when the solder melt take out the emitter with tweezers and put it over a wood or something like that, it's ceramic and a thermal shock could break it.
When the melt temperature is reached cut the power since for a while keep increasing even not powered
Take out the star and beat it against something hard while hot to clean the solder excess.
Solder
Wait till the plate is cold or warm, do not put a cold emitter over a hot surface.
Clean the star with alcohol , put the solder paste , not much , just a small quantity is enough, read about in the Cree's literature to more deep approach.
Put the star/emitter over the plate and wait, when the solder melt wait around 15 seconds and take out the star of the plate, this latest is the more delicate manoeuvre, could be doing with the tweezer or simply pushing out of the plate to a wood holded beside .
Some last, the hottest part is near the tip ..
Done.
I thought i went too far with the tips , hope you understand, i suspect reading it is a nighmare ..haha