An old friend of mine just sent me an email:
Long time no see! How are you?
I had to relocate recently because of my job...
New country, new city, no friends... Need somebody like you to hang out with!
If you'll find some free time, come and visit me!
I remember you like puzzling, so I'll give you a challenge!
I am currently based in
I hope I didn't make it too difficult. There's $3$ steps to decipher it:
1) change the system
Flight tickets & drinks are on me if you'll figure it out until the weekend!
Help me find the name of the city hidden in those numbers!
For the first step, you have to change the numerical system