To edit a library element either create a new one or open the library element from within the repository by doubleclick.
Library elements are mainly described by predefined properties. The library editor allows you to define, which properties can be edited after the library element has been inserted into a diagram and which not.
Locking and unlocking properties
To prevent a property from being changed within a process diagram close the lock of that property. The icon becomes a red closed lock.
To allow a property being changed within a process diagram open the lock of that property. The icon becomes a green open lock.