I have often used a an acupuncture needle to clear really cloggged nozzles, usually caused running woodfill filament. Heat nozzle up then push up through from nozzle whine in the printer.. Only a few dollars a packet on AliExpress.
and yes I have also removed and replaced worn 0.4 nozzles with a 0.8 nozzle off AliExpress - not that hard to do, just make sure you have the proper scanner and hold the heat block, not the thin collar.
was a easy way to get a .8 nozzle without buying one, and I already had a worn out printcore with 3000h on it. To use anyway.