Jens, has your friend had any luck since you first posted this? According to some cursory research, Lamchen Gyalpo Rinpoche has visited Riga, Latvia in the past, and I'm sure he'd come again if there's interest in arranging it.https://wn.com/mobile/drikung_lamchen_g ... _chod_puja
Gyalpo Rinpoche compiled a "medium-lengthed" Chöd text based on lots of sources from both inside and outside the Drikung Kagyu lineage, including citations of the scriptural basis from Sutras and the writings of Aryadeva. It includes the entire path from the Four Thoughts to all the various feasts, and even is interspersed with commentary and instructions on how to practice it in various lengths due to time constraints.
There is a series of videos on YouTube with Rinpoche teaching Chöd which I can provide you the link for if you PM me. Presumably he teaches from his own sadhana, though I haven't hunkered down to view them and be sure. Ratnashri Sweden has done the world a great service by compiling such an extensive archive of links that all seem to still be working.
In my experience over the years, usually the lamas could care less about a practitioner being poor or rich with regards to attending empowerments, transmissions, and teachings. It's usually the local sangha who is asking for entrance donations to recoup the cost of the lama's visit, since many are on shoestring budgets, and to be able to make a collective offering at the end.
I've been very fortunate to be allowed to attend most of the events I've been to on a work-study basis, so your friend should inquire about this with the organizing sanghas if he wants to attend. Often events are short on volunteers and can use all the help they can get, and thus will gladly take the extra set of hands as a win-win. If nothing else, inquire if their policy is to not refuse anyone due to lack of funds.
When you see how much money was offered in order to get Lamchen Gyalpo Rinpoche to compose his text, you'll realize the prices for attending events for exactly what they are.
"The Sutras, Tantras, and Philosophical Scriptures are great in number. However life is short, and intelligence is limited, so it's hard to cover them completely. You may know a lot, but if you don't put it into practice, it's like dying of thirst on the shore of a great lake. Likewise, a common corpse is found in the bed of a great scholar." ~ Karma Chagme དྲིན་ཆེན་རྩ་བའི་བླ་མ་སྐྱབས་རྗེ་མགར་ཆེན་ཁྲི་སྤྲུལ་རིན་པོ་ཆེ་ཁྱེད་མཁྱེན་ནོ།།