If you know what you are doing and are confident with dealing with this kind of hardware you can jump straight from step 8 to step 20 and complete this repair in a lot fewer steps.
If you are not 100% confident or otherwise the slightest bit concerned I recommend you follow every step in these instructions - they are the best on the net.
I didn't have any available, but I recommend the use of non-magnetic tools - especially tweezers - wherever possible when undertaking this repair due to the very strong magnet in the earpiece. Obviously you will have to use a metal screwdriver for the screws, but when it comes to the delicate micro-positioning of the replacement earpiece itself your life will be a lot easier than mine was if you employ plastic tools. Still, it is clearly possible with all metal tools, just a tad more fiddly and a tad more time-consuming. (But why make your life any more difficult than it truly has to be. :-) )
Methylated spirits will do it.
Use a very small amount on the corner of a lint-free cloth.
At a pinch you can use paper kitchen towel or one of those cotton earbud things. Whatever happens make sure that you don't accidentally leave any lint behind.
Don't let excess solvent flow anywhere except on the contacts. In fact, don't let it "flow" anywhere. You need enough on your cloth to whet the contact that needs to be cleaned but not so much that it is at risk of running off and getting into places you don't want it to.
Other solvents suitable for use on electrical contacts will also do but avoid any that leave a residue behind. Confusingly, it is often products labelled as 'Contact Cleaner' that leave a residue.
Quando lo avranno fatto, sarai in grado di visualizzare un grafico della reputazione guadagnata nel tempo da loro.
Ecco un'anteprima di come il grafico apparirà:
Ancora nessuna reputazione acquisita.