Purchase SOL (or USDT) from a major exchange (Coinbase, Binance) and send it to your personal wallet.
Download and install Phantom wallet or any other Solana compatible wallet to store your assets.
Visit Raydium, Jupiter, or DexScreener. Connect your wallet and select JLT to swap.
Paste the contract address, select the token, confirm the swap in your wallet, and you're done!