How to work for liberating ALL living beings? I am given to understand that a true Buddhist seeks tirelessly to liberate from the suffering (dukkha) of existence all living beings, and not only humans. Attainment of Buddhahood depends on such actions on an ongoing basis, I am told. Based on this, my question is: 

1) Apart from generally showing compassion and benevolence towards all living beings, in what ways do accomplished Buddhism practitioners work for the liberation of living being as diverse as, say, ants, pine trees, salmon and e-coli bacteria? What do the scriptures say, and what do the more recent writings say on this matter?

2) How do accomplished Buddhism practitioners liberate from dukkha the beings of non-earthly nature of other lokas, such as angry deities and hungry ghosts? What do the scriptures say, and what does recent literature say?
As per the "Heart Sutra in 8000 Lines", you liberate all sentient beings by attaining direct realization that in fact there are no any such "sentient beings" to talk about. "Sentient being" is only a nominal designation. Two keywords to study are anatta (sanskt., anatman) and shunyata.

Now, as a practice of paramitas (of generosity, forbearance, renunciation, loving-kindness, and equanimity), the commitment to staying in samsara and deferring one's own liberation until all sentient beings attain nirvana, requires complete surrendering of one's antipathy to samsara and craving for peace, complete surrendering of one's ego - which (the surrendering) paradoxically becomes the gate to Realization.