If you lose your Jason Key, the only way is Private Key. If you don't have PK, i think you have to make a new one and don't think again your old wallet. Say goodbye for it. RIP
I have my json key and that password I use for my daily banking activity. I never forgets it. but now its not allowing me to import it.
Where do you want to import it ?
I think very simple way to import coin, you just make a new wallet and paste your coin address to old wallet.
And then just click SEND. I think thats enought and very clear.