Swapping BNB from Binance Chain (BEP2) to Smart Chain (BEP20) using TrustWallet

In Trust Wallet, click on your BNB balance.

Then select "More" and from the popup menu select "Swap to Smart Chain".

Enter the amount ant tap "Swap". Do not swap all your BNB, leave about $5 worth of BNB in BEP2 network in order to cover future network fees for moving BUSD from BEP2 to BEP20. At the time of writing $5 is about 0.011 BNB.

Tap "Confirm" on the next screen and wait several minutes. Trust Wallet will show a message saying "Processing. It might take a few minutes".