How can Kundalini be awakened? Would Japa alone be successful in awakening the Kundalini?

Kundalini can be awakened by the practice of Asan, Pranayam, Mudras, Japa and by the grace of a Guru. Refer to my book "Kundalini Yoga".

Yes. Japa alone is quite sufficient to awaken the Kundalini. There is no doubt of this. Sri Samarth Ramdas awakened the Kundalini by doing Japa of the Mantra Om Sri Ram Jaya Ram, Jaya Jaya Ram thirteen crores of times by standing in the river Godavari, in Takli Village, near Nasik.

Swami Sivananda