Download Phantom or your wallet of choice from the app store or google play store for free. Desktop users, download the google chrome extension.
Have SOL in your wallet to switch to $DIET. If you don't have any SOL, you can buy directly on Phantom, transfer from another wallet, or buy on another exchange and send it to your wallet.
Connect to Raydium or Jupiter. Go to raydium.io in google chrome or on the browser inside your Phantom app. Connect your wallet.
Paste the $DIET token address into Raydium, select Diet, and confirm. When Phantom prompts you for a wallet signature, sign it to finalize the trade.