RE: Uniswap, Hard Fork Delay, & Other Updates

It will be through the Splinterlands website, yes. The original post had some more information:

At the end of each of the 30 day periods there will be an option on the Splinterlands website for participants to claim their rewards. Claiming the rewards will require signing a message with the private keys of the Ethereum wallet that has provided liquidity to the pool over the past 30 days. If that sounds complicated, don't worry - there will just be a simple button to press which will pop up a Metamask window (or web3 Ethereum wallet of your choice) that will allow you to sign the message and get your rewards.