To free Bellhart in Hollow Knight: Silksong, the key steps are:

1. Progress to Shellwood and defeat Sister Splinter, the area boss there.
2. After defeating Sister Splinter, unlock the Cling Grip ability (a wall-climbing skill).
3. Use the Cling Grip to access the upper section of Bellhart, which is otherwise unreachable.
4. Navigate through Bellhart’s upper tunnels, breaking bell walls and defeating enemies until you reach the boss called Widow.
5. Defeat Widow to break the silken curse on Bellhart.
6. After defeating Widow, collect the Needolin ability.
7. Return to Bellhart, ring the giant bell to fully free the town, restoring access to shops, NPCs, and the Wish Board for quests and upgrades.

Additional notes:

• While progressing, you can rescue a lost Flea in Bellhart.
• You can donate Rosaries to the Bellhart Wishwell to help restore the town.
• Some shortcut paths open up to make future travel easier.

This sequence is critical for progressing through the game’s story and unlocking Bellhart’s services and quests.