Actually, you can't.
You need to put your bip39 seed in coinomi bip 39, and then you will get the xmr seed
https://coinomi.github.io/tools/bip39/
So you need to use this XMR seed. You can't import the bip39 seed into moneruju or cake wallet.
OK, that's on me for not being clear.
BUT I was going with the *assumption* that if you put your seed in X to get seed Y that someone can run it backwards and if you put seed Y into something you get seed X
I could be 100% wrong on that but I can't see it not working.
But either way we are still just talking about XMR, as other coins have stopped working you are still going to have to move them someplace else. So wither you export the keys one at a time and import them into another wallet OR you move your seed.
Would be better just to move what you can by just sending the coins that still work with a normal transaction and then getting out the other ones however you like and just assuming all seeds / addresses are compromised.
Once again I use coinomi but the value of the coins there is worth less then the phone they are on so it's an acceptable risk for me at the moment.
-Dave