Here's how you can do that:
On the website: https://youtu.be/RtBTXig7Xjo
On the app:
Dashboard → The goal from which you want to withdraw → More → Redeem → Select any reason for redeeming → Either enter the amount you want to redeem or use any shortcuts such as Redeem all, Redeem All Exit load free, etc. → Review and Confirm Redemption.