1) go to a doctor, NP, or other medical practitioner with prescription power
2) convince them to write you the script (and pay them, directly or indirectly, for this service)
3) have it sent electronically (in NY) to the right pharmacy that can fill it
4) then go to the pharmacy and fill it
The rent-seeking in our medical system will be the death of us.
Regulations are written in blood.
Edit: but yes, this process will have to be simplified in every country if it turns out to be the primary recourse.
A "while" here means months, or even years. In fact, many people with Lupus or RA take this for years.
One terrible solution we have in the USA because we refuse to see healthcare as a right (omg we can't have everyone healthy or too healthy) is many states have practicing nurses as pseudo-doctors at some pharmacies (ie. CVS "Minute Clinic") where you give them $100 to be seen, and then they write a script. It's disgusting but it's a solution.