Short answers, pulled from the story.
The Nepal Bhasa renaissance was a spontaneous movement to revive and modernize the Nepal Bhasa language, active from 1909 to 1941. It was not centrally organized, but produced lasting achievements in grammar, education, translation, and literary standardization.
The Four Pillars of Nepal Bhasa were Nisthananda Bajracharya, Siddhidas Mahaju, Jagat Sundar Malla, and Yogbir Singh Kansakar. All four were among the most prominent figures of the renaissance era.
The first printed book in Nepal Bhasa was Ek Binshati Pragyaparmita, authored and printed by Nisthananda Bajracharya in 1909. He brought printing type from Kolkata and carried out the typesetting, proof-reading, and printing himself.
Shukraraj Shastri published the first Nepal Bhasa grammar book, called Nepalbhasa byakaran, in N.S. 1048. Before this, grammar was transmitted only through manuscripts and traditional teachings with wide variability.
Jagat Sundar Malla turned his own house into a free school and wrote many course books to fill the gap in teaching materials. He published a dictionary, an English-Nepal Bhasa translation, and in 1915 translated Aesop's Fables into Nepal Bhasa.
The term "Newari" was a name imposed by the Khas people, and renaissance figures including Dharmaditya Dharmacharya actively promoted the proper name "Nepal Bhasa" in its place. The push to restore the language's original name was seen as part of its broader revival and identity.