not sure what programs i need to download though.
I'll see if I can lay it out step by step. Some of these steps will be optional depending on how paranoid you are about security and how much money we're talking about. I'll leave that judgement for you to make.
Make a backup:So yep, that screenshot shows the message about making a backup. Should be a simple process (but again, I've never used that particular wallet).
[optional] If you want to be extra security-conscious, don't transfer your backup from your android device to your PC just yet. Wait until
after you've downloaded all the bits you need and then disconnected from the internet. Also ensure your PC is clean of any viruses and such.
Stuff to download:As per
this post, you'll need
decrypt_bitcoinj_seed and the Python + Protobuf and pylibscrypt bits detailed on that page.
Then go to the
Mnemonic Code Converter[optional] right click somewhere on that page and save it to your PC.
[optional] Maybe save a copy of HCP's post too if you're doing if all offline for security.
And lastly, (if you don't already have one) you'll need a BCH wallet. It's up to you if you want another android one or a desktop wallet for your PC. You might find desktop easier for importing the key. But then, you'd probably want an SPV lightweight client where you don't have to download the entire blockchain. My understanding is that "Electron Cash" is a popular choice (but I'm not an expert on BCH by any means). As I mentioned before, make sure it's legitimate software. Don't get phished by downloading a fake.
Recovery steps:[optional] Now, disconnect from the internet and close any unnecessary programs.
Transfer your backup file from your android device to your PC.
Run decrypt_bitcoinj_seed on your backup as per the instructions. That should give you the magic 12 seed words you need.
Put the seed words into the Mnemonic Code Converter, following those instructions from the linked post.
From the results generated, find the private key which corresponds with the BTC address you mistakenly sent your BCH coins to.
Import
that private key into your BCH wallet.
[optional] Remove any trace of the private key and seed words from your PC and then reconnect to the internet.
Fingers crossed, you should have access to your coins again.