Ok guys....I've just finished doing it...
I disassembled a CN gmt (cyclope was to far right)... popped out the crystal... heated, hitted with a knife => cyclope popped, crystal cleaned, back on the work bench....reassembled!
Tomorrow I'll go to buy some UV cement or glass glue.
It was hard... (I'm a noob)
Some advices for those who are brave and want to try to heat the crystal:
Acetone wasn't working, so I used HEAT. A LOT....yeah, you are trying and isn't working?
Don't be afraid, it won't explode. Use MORE heat!
I said MORE .
And then, suddenly, the cyclope change colour....that's the time!
Hit the cyclope with a knife....et voil