How to Send Total Balance

I am changing wallets.

How do I send the total balance?

You would see how much you have in your wallet. I don't know what wallet you are currently using, but they would usually tell you have much you have in total. Put that number in the "send" and make sure you leave some for a transaction fee.

Depends on if some/all of your funds are held in shielded addresses. If so, you'll need to use a z_sendmany for each shielded address that has funds in it to send the total balance of each into a new address. Any funds in transparent addresses can be spent with a single sendmany to a new address.

Check zcash-cli help z_sendmany and/or zcash-cli help sendmany for how to structure the transactions.