Need help with core files!! How to change title and desc?

Hello,

I need to make some changes in vBSEO plugin. I need a little bit change title with my variables, also description. Ok, I'll tryied to find that in vBSEO files, but it's very hard coded no comments, etc. With a lot of functions where is $title variables and etc, so my search goes bad. Main question, in which vBSEO plugin file and which function do changes for forum <title></title> and which function do changes for forum post description tag?

Duplicate.