Login to Kine exchange with same address used in testnet, and navigate to Balance page,
Eligible user will be able to see the claim rewards button with the amount (25/50) of KINE available.
Minimum 1$ trade is required before claiming the rewards,
Transfer kUSD to Cross margin account and complete a trade, details of how to trade can be found here.
Now go back to Balance page and click "claim" again, sign the transaction and wait a bit, KINE will be allocated to your Metamask wallet.