This was getting a bit long to be a comment on your question. I'm not sure this is really adequate for an "answer."
The article could be better. If you scan through doing a search on "perfection," it shows that the first six bhumis follow the 6 paramitas. Reading the section on the seventh Bhumi claims that someone at the 7th can practice all the perfections at once. This implies that each bhumi beforehand is the stage at which individual traits are perfected; suggesting someone at the 1st bhumi has perfected generosity.
So the practice manual for reaching each bhumi would be the same as any practice manual or instructions as the Mahayana paramitas. For that, I would point you towards your favorite Lamrim text, as the paramitas are the path of sutra. I'm a fan of Gampopa's "Jewel Ornament of Liberation."