Open AssetX, and make sure you are in Liquidity. If you are not, you can navigate there by using the menu on the left (desktop), or on the bottom footer (mobile).
Liquidity on AssetX
Make sure your wallet is connected, and select which tokens you would like to pool.
Selecting which tokens you would like to pool
Input amounts and initialize Liquidity Pool.
Initializing a Liquidity Pool
Note: If a Liquidity Pool of these tokens already exists, you will be notified, and can place your tokens in the pool instead.