The example wallet used for this tutorial is MetaMask.
1) Go to https://wallet.matic.network/ and connect using MetaMask.
2) You should be prompted by MetaMask for a Signature Request. Click the Sign button.
3) Next click the button Move Funds to Matic Network.
4) The Transfer window will open. The token shown by default on the transfer module will be Ether. You can choose to move other tokens by clicking the arrow and selecting.
5) Select the MATIC token in the dropdown menu, enter the amount you would like to move, and then click the Transfer button. The system will display a warning message, click the Continue button.
6) The Transfer Overview window displays the costs overview for moving the funds. You may need to approve an additional spend approval transaction, the first time you move an asset via the bridge. If / when ready click the Continue button.
7) Make sure the Transfer Mode required is selected (Plasma Bridge for MATIC when transferring into the Polygon (MATIC) Network), then click the Continue button. A MetaMask window should open and then click Confirm.
8) After confirming the transaction will process. It should take around 7-8 minutes to move your funds to the Polygon (MATIC) Network.
9) After completion - your funds will still be in your wallet, but now on the Polygon (MATIC) Network and available for use on the PolyZap Decentralized Exchange (AMM) and Yield Farm.
Note: full credit to the WowDegen article here for this information, that we've copied (in part) to include here for easy reference.