Go to: <YOUR WOW FOLDER>\WTF\Account\<ACCOUNTNAME>\SavedVariables
Remember to make a backup of your GatherMate2.lua just incase anything goes wrong.
Scroll down to GatherMate2.lua => Open it in your favorite texteditor (Notepad etc) => Scroll down to the bottom where it says: GatherMate2ArchaeologyDB = {
}
Copy the information from http://pastie.org/private/9w25jbigql6z1ngxr9kbxw and overwrite the above mentioned text.
If you already have data from before you might want to consider using GatherMate2_Data and doing the same but locate:
World of Warcraft\Interface\Addons\GatherMate2_Data\ArchaeologyData.lua
and paste it there instead. Then you open wow and write /gathermate2 locate the one called Import from the menu click on merge and finally import.