There are several ways to reset your skills and ranks in Diablo 4. To reset all your skill points and ranks, simply click "Refund All" at the bottom of the skill tree. If you only need to reset individual skills and ranks, you can do so, but there is a gold cost associated with it. It's worth noting that the D4 gold cost increases as you level up and want to reset more points.

During the Diablo 4 Open Beta, it was discovered that resetting is free until Level 7. After that, the cost starts at just 1 Gold, but by Level 25, it already costs 222 Gold to reset a rank or skill.

It's important to keep in mind that you can only reset a point in the Diablo 4 Skill Tree if it doesn't break any dependencies. 

For example, if you want to reset a skill that unlocks another skill at the end of a branch, you'll need to reset the entire branch.