Can you "visualize" the Buddhadharmas in front -(I mean sitting in front of)- your computer monitor? . . .
When you practice Medicine Buddha, turn off the computer, tv, radio, etc. Sit in a chari or on a cushion. Take refuge in the Buddha, Dharma and Sangha. You can imagine (this is a visualization) the Buddha or the Medicine Buddha representing all the Buddhas, also as the proclaimer of the Dharma (or the embodiment of the Dharma) and even the embodiment of the Sangha in his own body (or you can be a little more elaborate and imagine all the Arhats and Bodhisattvas and all the Buddhas of past, present and future surrounding him). So even this visualization as imagination can be condensed and simple (just imagine the Buddha or Medicine Buddha) or more complex as you prefer and can visualize. Or you just just feel that they are in front of you slightly higher than your head.
Create the mind of lovingkindness and universal compassion for all beings. Raise the intention of practicing in order to liberate all beings everywhere and ultimately recuse them from samsara.
Then go though the text you are using. If you are using the Thrangu Rinpoche book he has two text's from memory. One is sort of esoteric (dealing explicitly with light from the five elements and) so don't do that one (that one also doesn't have the mantra I think). The text will have the first two steps that I mentioned above. At the end of the practice dedicate the merit that you generated to liberate all beings.