If your sOHM is not being used as collateral on Fuse or another platform,
You just need to go to the Olympus Dao website, select stake from list of options on the left side of the page, and choose the unstake option.
https://app.olympusdao.finance/#/stake
Once the process is complete, the Ohm appears in your ethereum wallet, and you can swap it for ether or stablecoins, move it to an exchange, and sell whatever crypto asset you chose for USD.
If you have more questions you can go to the Olympus Discord and ask the community.
