How to upgrade from 2.5 to 3.x

Hi,
I'm using Joomla 2.5 with "League" template and planning to migrade to J3.x since support to J2.5 is EOL.
Do you have any specific instructions how to do this with less destruction.
Thank you.

http://www.buchholzfootball.com.

Here you have general informations:
https://www.gavick.com/documentation/un ... 3-2-safely
https://www.gavick.com/documentation/jo ... joomla-3-3

And here you will find some info on possible problems and the way to slve:
https://www.gavick.com/forums/startup-j ... -3-1-28953