According to Kejawen (Javanese mysticism) it is achieved by constantly and mindfully attempting to incorporate the following values in life: nonattachment/freedom from selfish attachment (rila); gratefully accepting life as it comes (nrima); mindfulness in all thoughts, words and deeds (waspada-eling); humility/humbleness (andap-asor); modesty (prasaja); and patience (sahar). Another way is ‘to be concerned’, to exercise solicitude, known as prihatin, through minor ascetic observances. यवद्वीप के रहस्यवादियों के मतानुसार अनासक्ति, स्वीकृति, स्मृति-उपस्थान, विनय, सादगी, धैर्य एवं एकान्तप्रेम – जीवन में स्वार्थशून्यता को उपलब्ध करने के बस यही तो कुछ सोपान हैं।
I have been trying to become selfless and successfully I've become selfless. I found my peace, joy and happiness in life and as long as I can have that everyday I can continue to be selfless.
You can implement selflessness by self realization which can be achieved by meditation and prayer. You have to think beyond this world and always look to help others which will give you a great kind of inner satisfaction and happiness.