Clearly a sensitive topic. When a long-term user of this site posts such a delicate question, other members of the community will have many concerns, and will take appropriate action (as seen above).
Nevertheless the question has been asked., and this site is set up to provide answers.
The Dignitas clinic is in Forch, Switzerland. A short bus ride from Zurich.
There is another clinic offering similar services, called 'Eternal Spirit'
http://www.dignitas.ch/
https://www.lifecircle.ch/?l=en
Dignitas has a lot of advice on its site about making a dignifed exit. The costs are quite high - think £10,000.
This article is a useful resource:
https://www.independent.co.uk/life-style/health-and-families/the-true-cost-how-the-uk-outsources-death-to-dignitas-a8073401.html
To summarise the article, it is painful for those left behind, as there is a great deal of administration to go through in Switzerland to prove there was no wrongdoing, and few bring the body home, as the UK authorities may wish to take an interest in an unnatural death.
The near-unanimous option is a cremation in Switzerland. That, too may not be the preferred option for family and friends.
Even so, some returning family members have been questioned by Police over an unnatural death. It is currently illegal in the UK to assist someone to die.
Another factor is that one must have reasonable health before attempting the journey to Switzerland. This suggests that the journey must be undertaken before the end is in sight, and may rob family and friends of precious time with the patient while he/she is still (relatively) healthy.
if anyone is thinking about that option, the Dignitas site as good a first step as any.
The article from the Independent also suggests that the process is far from satisfactory for those left behind. However, despite the drawbacks, most surviving relatives say the experience was less negative than the alternatives - which (in my opinion) says something very negative about the end-of-life experience in the UK.