Upgrading Router
From CTWUG Wiki
Here are the steps to upgrading your Mikrotik Router OS.
Finding your unique Architecture name
Before starting find out your router's Architecture Name
Downloading RouterOS
Once you have the router's architecture name, you can proceed to download the specific package/version you require by logging onto http://mt.ctwug.za.net/files/
Upgrading...
Once you have the file you want, you can then proceed to start upgrading your system.
I've only done it two ways, both which are pretty easy: