I know this has been released before, but I noticed no one has either updated it and/or told people how to update/what to do.
It's very simple and takes less than 1 minute to do.
Video/Video Tutorial
Text Tutorial
1) Open DNSpy or your choice of decompiler
2) Drag Assembly-CSharp.dll into the decompiler
3) Search for CanJump
4) Change
toCode:return (this.IsGrounded() || this.jumpForgivenessLeft > 0f) && this.entity.visualState != Entity.State.Dead && !this.entity.HasStatus(Entity.StatusType.NoMovemen t);
5) SaveCode:return this.entity.visualState != Entity.State.Dead && !this.entity.HasStatus(Entity.StatusType.NoMovemen t);
6) Enjoy infinite jumping