Switch from "regular" health insurance to Swisscare

Hello, I am a PhD student at UZH and I have a question about the possibility to be insured with Swisscare. Currently, I am insured with Assura since I spent an internship in a company here in Switzerland before starting my PhD and I had to choose a "regular" (meaning not one that lets you get an exemption) health insurance (I was in Aargau). I would like to switch to Swisscare at the end of this year, does anybody know if this is possible since I am already insured with a regular insurance company? Can I just send Assura a letter where I ask to terminate my insurance at the end of the year and ask Swisscare to be insured by them, or is there some more complicated procedure to follow?

Thank a lot!
Cheers
Davide

Switch from "regular" health insurance to Swisscare